Subj : Southern Ontario Weather To : All From : Northern Realms Date : Thu Jul 31 2025 15:35:00 FPCN11 CWTO 311930 Forecasts for Southern Ontario and the National Capital Region issued by Environment Canada at 3:30 p.m. EDT Thursday 31 July 2025 for tonight Friday and Friday night. The next scheduled forecast will be issued at 5:00 a.m. EDT Friday. City of Toronto. Tonight..Partly cloudy. Low 14. Friday..Mainly sunny. High 24. UV index 8 or very high. Friday night..Clear. Wind north 20 km/h becoming light after midnight. Low 15. Windsor - Leamington - Essex County. Tonight..A few clouds. Local smoke this evening. Wind northeast 20 km/h gusting to 40 becoming light late this evening. Low 12. Friday..Sunny. Wind becoming northeast 30 km/h in the morning. High 24. Humidex 25. UV index 9 or very high. Friday night..Clear. Wind northeast 30 km/h becoming light near midnight. Low 14. Chatham-Kent - Rondeau Park. Tonight..Partly cloudy. Clearing near midnight. Local smoke this evening. Wind east 20 km/h gusting to 40 becoming light early this evening. Low 10. Friday..Sunny. Becoming a mix of sun and cloud in the afternoon. Wind becoming north 30 km/h late in the morning. High 24. Humidex 25. UV index 9 or very high. Friday night..Clear. Wind north 30 km/h becoming light in the evening. Low 9. Sarnia - Petrolia - Western Lambton County. Tonight..Partly cloudy. Clearing this evening. Local smoke this evening. Wind north 30 km/h gusting to 50. Low 12. Friday..Sunny. Wind becoming north 30 km/h gusting to 50 late in the morning. High 25. Humidex 27. UV index 9 or very high. Friday night..Clear. Wind north 30 km/h gusting to 50 becoming light near midnight. Low 10. Watford - Pinery Park - Eastern Lambton County. Tonight..A few clouds. Local smoke this evening. Wind northeast 20 km/h gusting to 40 becoming light this evening. Low 12. Friday..A mix of sun and cloud. High 25. Humidex 27. UV index 9 or very high. Friday night..Clear. Low 10. Rodney - Shedden - Western Elgin County. Tonight..Partly cloudy. Clearing late this evening. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light this evening. Low 11. Friday..Sunny. Becoming a mix of sun and cloud near noon. Wind becoming north 20 km/h late in the morning. High 26. Humidex 28. UV index 9 or very high. Friday night..Clear. Low 11. St. Thomas - Aylmer - Eastern Elgin County. Tonight..Partly cloudy. Becoming clear this evening. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light this evening. Low 11. Friday..Sunny. Becoming a mix of sun and cloud near noon. Wind becoming northeast 20 km/h late in the morning. High 26. Humidex 28. UV index 9 or very high. Friday night..Clear. Low 11. Strathroy - Komoka - Western Middlesex County. Tonight..Partly cloudy. Clearing late this evening. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light early this evening. Low 11. Friday..Mainly sunny. Wind becoming north 20 km/h late in the morning. High 26. Humidex 27. UV index 9 or very high. Friday night..Clear. Wind north 20 km/h becoming light in the evening. Low 10. London - Parkhill - Eastern Middlesex County. Tonight..A few clouds. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light early this evening. Low 11. Friday..Sunny. Becoming a mix of sun and cloud near noon. Wind becoming north 20 km/h late in the morning. High 26. Humidex 27. UV index 9 or very high. Friday night..Clear. Low 10. Simcoe - Delhi - Norfolk. Tonight..Clear. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light this evening. Low 10. Friday..Sunny. Becoming a mix of sun and cloud near noon. Wind becoming northeast 20 km/h late in the morning. High 26. Humidex 28. UV index 9 or very high. Friday night..Clear. Low 8. Dunnville - Caledonia - Haldimand. Tonight..Clear. Becoming partly cloudy late this evening. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light this evening. Low 11. Friday..A mix of sun and cloud. High 24. Humidex 26. UV index 9 or very high. Friday night..Clear. Low 10. Woodstock - Tillsonburg - Oxford County. Tonight..A few clouds. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light early this evening. Low 11. Friday..Sunny. Becoming a mix of sun and cloud near noon. High 25. Humidex 26. UV index 8 or very high. Friday night..Clear. Low 9. Brantford - County of Brant. Tonight..A few clouds. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light early this evening. Low 11. Friday..Sunny. Becoming a mix of sun and cloud near noon. Wind becoming northeast 20 km/h late in the morning. High 25. Humidex 26. UV index 8 or very high. Friday night..Clear. Low 9. Niagara Falls - Welland - Southern Niagara Region. Tonight..A few clouds. Local smoke early this evening. Wind east 20 km/h becoming light this evening. Low 13. Friday..Mainly sunny. Wind northeast 20 km/h becoming light late in the morning. High 25. Humidex 27. UV index 9 or very high. Friday night..Clear. Low 13. St. Catharines - Grimsby - Northern Niagara Region. Tonight..Partly cloudy. Local smoke early this evening. Wind east 20 km/h gusting to 40 becoming light this evening. Low 13. Friday..Mainly sunny. High 25. Humidex 27. UV index 9 or very high. Friday night..Clear. Low 13. City of Hamilton. Tonight..A few clouds. Local smoke early this evening. Wind east 20 km/h gusting to 40 becoming light this evening. Low 13. Friday..Mainly sunny. Wind northeast 20 km/h becoming light in the afternoon. High 24. Humidex 26. UV index 9 or very high. Friday night..Clear. Low 11. Burlington - Oakville. Tonight..Partly cloudy. Local smoke early this evening. Wind east 30 km/h becoming light early this evening. Low 13. Friday..Mainly sunny. High 24. Humidex 25. UV index 8 or very high. Friday night..Clear. Low 13. Halton Hills - Milton. Tonight..A few clouds. Local smoke early this evening. Wind east 20 km/h gusting to 40 becoming light early this evening. Low 13. Friday..Mainly sunny. High 24. Humidex 25. UV index 8 or very high. Friday night..Clear. Low 13. Mississauga - Brampton. Tonight..Partly cloudy. Low 13. Friday..Mainly sunny. High 24. Humidex 25. UV index 8 or very high. Friday night..Clear. Low 13. Caledon. Tonight..Partly cloudy. Wind northeast 20 km/h becoming light early this evening. Low 13. Friday..Sunny. High 24. Humidex 25. UV index 8 or very high. Friday night..Clear. Low 13. Vaughan - Richmond Hill - Markham. Tonight..Partly cloudy. Wind southeast 20 km/h becoming light early this evening. Low 12. Friday..Mainly sunny. High 25. UV index 8 or very high. Friday night..Clear. Low 11. Newmarket - Georgina - Northern York Region. Tonight..Partly cloudy. Low 12. Friday..Mainly sunny. High 25. UV index 8 or very high. Friday night..Clear. Low 11. Pickering - Oshawa - Southern Durham Region. Tonight..Partly cloudy. Wind southeast 20 km/h becoming light early this evening. Low 12. Friday..Mainly sunny. High 25. UV index 8 or very high. Friday night..Clear. Low 11. Uxbridge - Beaverton - Northern Durham Region. Tonight..Partly cloudy. Low 12. Friday..Mainly sunny. High 25. UV index 8 or very high. Friday night..Clear. Low 11. Goderich - Bluewater - Southern Huron County. Tonight..Clearing early this evening. Local smoke early this evening. Wind north 30 km/h becoming light late this evening. Low 10. Friday..Sunny. Wind becoming northeast 20 km/h then northwest 30 late in the morning. High 25. UV index 8 or very high. Friday night..Clear. Wind north 30 km/h becoming light in the evening. Low 9. Wingham - Blyth - Northern Huron County. Tonight..Clear. Local smoke early this evening. Wind north 20 km/h becoming light this evening. Low 10. Friday..Mainly sunny. Wind northeast 20 km/h becoming light in the afternoon. High 25. UV index 8 or very high. Friday night..Clear. Low 9. Stratford - Mitchell - Southern Perth County. Tonight..Partly cloudy. Clearing this evening. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light late this evening. Low 10. Friday..Sunny. Wind becoming north 20 km/h late in the morning. High 25. UV index 8 or very high. Friday night..Clear. Low 9. Listowel - Milverton - Northern Perth County. Tonight..Clearing early this evening. Local smoke early this evening. Wind north 20 km/h becoming light this evening. Low 10. Friday..Sunny. Wind northeast 20 km/h becoming light in the afternoon. High 25. UV index 8 or very high. Friday night..Clear. Low 9. Kitchener - Cambridge - Region of Waterloo. Tonight..Partly cloudy. Clearing this evening. Local smoke early this evening. Wind northeast 20 km/h gusting to 40 becoming light early this evening. Low 12. Friday..Sunny. High 24. Humidex 25. UV index 8 or very high. Friday night..Clear. Low 9. Guelph - Erin - Southern Wellington County. Tonight..Partly cloudy. Clearing this evening. Local smoke early this evening. Wind northeast 20 km/h becoming light early this evening. Low 12. Friday..Sunny. High 24. Humidex 25. UV index 8 or very high. Friday night..Clear. Low 9. Mount Forest - Arthur - Northern Wellington County. Tonight..Clear. Local smoke early this evening. Wind north 20 km/h becoming light this evening. Low 12. Friday..Sunny. Wind north 20 km/h becoming light in the afternoon. High 24. Humidex 25. UV index 8 or very high. Friday night..Clear. Low 9. Orangeville - Grand Valley - Southern Dufferin County. Tonight..A few clouds. Wind north 20 km/h becoming light this evening. Low 15. Friday..Sunny. Wind becoming northeast 20 km/h late in the morning. High 23. UV index 8 or very high. Friday night..Clear. Low 10. Shelburne - Mansfield - Northern Dufferin County. Tonight..A few clouds. Wind north 20 km/h becoming light this evening. Low 15. Friday..Sunny. Wind northeast 20 km/h becoming light in the afternoon. High 23. UV index 8 or very high. Friday night..Clear. Low 10. Innisfil - New Tecumseth - Angus. Tonight..Partly cloudy. Wind northwest 20 km/h becoming light this evening. Low 15. Friday..Sunny. Wind becoming north 20 km/h late in the morning. High 23. UV index 8 or very high. Friday night..Clear. Low 10. Saugeen Shores - Kincardine - Southern Bruce County. Tonight..Clear. Local smoke early this evening. Wind north 30 km/h becoming light this evening. Low 13. Friday..Mainly sunny. Wind becoming north 30 km/h in the morning. High 23. Humidex 25. UV index 8 or very high. Friday night..Clear. Wind north 20 km/h becoming light in the evening. Low 13. Bruce Peninsula - Sauble Beach - Tobermory. Tonight..Clear. Becoming partly cloudy this evening. Low 13. Friday..Sunny. High 23. Humidex 25. UV index 8 or very high. Friday night..Clear. Low 13. Hanover - Dundalk - Southern Grey County. Tonight..Clear. Low 14. Friday..Sunny. Wind northeast 20 km/h becoming light in the afternoon. High 22. UV index 8 or very high. Friday night..Clear. Low 10. Owen Sound - Blue Mountains - Northern Grey County. Tonight..Clear. Becoming partly cloudy after midnight. Wind north 20 km/h becoming light early this evening. Low 14. Friday..Clearing in the morning. High 22. UV index 8 or very high. Friday night..Clear. Low 10. Barrie - Collingwood - Hillsdale. Tonight..Partly cloudy. Low 13. Friday..Sunny. Wind becoming north 20 km/h late in the morning. High 23. UV index 8 or very high. Friday night..Clear. Low 10. Midland - Coldwater - Orr Lake. Tonight..Partly cloudy. Wind becoming northeast 30 km/h this evening. Low 13. Friday..Sunny. Wind becoming northwest 30 km/h late in the morning. High 24. UV index 8 or very high. Friday night..Clear. Wind northwest 30 km/h becoming light in the evening. Low 17. Orillia - Lagoon City - Washago. Tonight..Partly cloudy. Wind northeast 20 km/h becoming light after midnight. Low 13. Friday..Sunny. Wind becoming northwest 20 km/h late in the afternoon. High 24. UV index 8 or very high. Friday night..Partly cloudy. Becoming clear in the evening. Wind northwest 30 km/h becoming light after midnight. Low 17. Cobourg - Colborne - Western Northumberland County. Tonight..Clear. Wind northeast 20 km/h becoming light this evening. Low 13. Friday..Sunny. Wind becoming northeast 20 km/h late in the morning. High 25. UV index 8 or very high. Friday night..Clear. Low 12. Belleville - Quinte West - Eastern Northumberland County. Tonight..Clear. Wind northeast 20 km/h becoming light this evening. Low 13. Friday..Sunny. Wind becoming northeast 20 km/h late in the morning. High 25. UV index 8 or very high. Friday night..Clear. Low 12. Picton - Sandbanks Park. Tonight..Clear. Wind northeast 20 km/h becoming light this evening. Low 13. Friday..Sunny. Wind becoming northeast 20 km/h late in the morning. High 25. UV index 8 or very high. Friday night..Clear. Low 10. Napanee - Consecon. Tonight..Clear. Wind northeast 20 km/h becoming light this evening. Low 13. Friday..Sunny. Wind becoming northeast 20 km/h late in the morning. High 25. UV index 8 or very high. Friday night..Clear. Low 10. Kingston - Odessa - Frontenac Islands. Tonight..Clear. Wind northeast 20 km/h. Low 13. Friday..Sunny. Wind northeast 20 km/h becoming light late in the morning. High 25. UV index 8 or very high. Friday night..Clear. Low 10. Lindsay - Southern Kawartha Lakes. Tonight..Mainly cloudy. Low 10. Friday..Mainly sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 8. Fenelon Falls - Balsam Lake Park - Northern Kawartha Lakes. Tonight..Partly cloudy. Low 10. Friday..Sunny. Becoming a mix of sun and cloud near noon. High 24. UV index 8 or very high. Friday night..Clear. Low 8. Peterborough City - Lakefield - Southern Peterborough County. Tonight..Partly cloudy. Low 10. Friday..Mainly sunny. High 24. UV index 8 or very high. Friday night..Partly cloudy. Becoming clear in the evening. Low 8. Apsley - Woodview - Northern Peterborough County. Tonight..Clearing. Low 10. Friday..Sunny. Becoming a mix of sun and cloud in the afternoon. Wind becoming northeast 20 km/h late in the morning. High 24. UV index 8 or very high. Friday night..Clear. Low 8. Stirling - Tweed - Madoc. Tonight..A few clouds. Low 13. Friday..Sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 10. Tamworth - Sydenham - South Frontenac. Tonight..A few clouds. Low 13. Friday..Sunny. Wind north 20 km/h becoming light late in the morning. High 24. UV index 8 or very high. Friday night..Clear. Low 10. Kaladar - Bannockburn - Bon Echo Park. Tonight..Partly cloudy. Becoming clear after midnight. Low 12. Friday..Sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 9. Bancroft - Hastings Highlands - Denbigh. Tonight..Mainly cloudy. Clearing this evening. Low 8. Friday..Sunny. Becoming a mix of sun and cloud in the afternoon. High 23. UV index 8 or very high. Friday night..A few clouds. Low 11. Gananoque - Mallorytown. Tonight..Clear. Wind northeast 20 km/h. Low 10. Friday..Sunny. Wind northeast 20 km/h becoming light in the morning. High 24. UV index 8 or very high. Friday night..Clear. Low 9. Brockville - Prescott. Tonight..Clear. Low 10. Friday..Sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 9. Westport - Charleston Lake. Tonight..A few clouds. Wind northeast 20 km/h. Low 10. Friday..Sunny. Wind northeast 20 km/h becoming light in the morning. High 24. UV index 8 or very high. Friday night..Clear. Low 9. Merrickville-Wolford - Kemptville. Tonight..Clearing. Low 10. Friday..Sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 9. Ottawa North - Kanata - Orl‚ans. Tonight..Clearing. Low 13. Friday..Sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 11. Ottawa South - Richmond - Metcalfe. Tonight..Clearing. Low 13. Friday..Sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 11. Gatineau. Tonight..Partly cloudy. Becoming clear this evening. Low 13. Friday..Sunny. High 25. UV index 8 or very high. Friday night..Clear. Low 9. Prescott and Russell. Tonight..Clearing. Low 15. Friday..Mainly sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 10. Morrisburg - Long Sault. Tonight..A few clouds. Low 12. Friday..Mainly sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 8. Cornwall - Lancaster. Tonight..A few clouds. Low 12. Friday..Clearing in the morning. High 24. UV index 8 or very high. Friday night..Clear. Low 8. Winchester - Newington. Tonight..Clearing. Low 12. Friday..Mainly sunny. High 24. UV index 8 or very high. Friday night..Clear. Low 8. Maxville - Alexandria. Tonight..A few clouds. Low 11. Friday..Clearing in the morning. High 24. UV index 8 or very high. Friday night..Clear. Low 8. Plevna - Sharbot Lake - Western Lanark County. Tonight..Partly cloudy. Clearing after midnight. Low 12. Friday..Sunny. High 23. UV index 8 or very high. Friday night..Clear. Low 10. Smiths Falls - Perth - Eastern Lanark County. Tonight..Partly cloudy. Becoming clear this evening. Low 12. Friday..Sunny. High 23. UV index 8 or very high. Friday night..Clear. Low 10. Port Carling - Port Severn. Tonight..Partly cloudy. Wind becoming northeast 20 km/h this evening. Low 15. Friday..Sunny. Becoming a mix of sun and cloud near noon. Wind becoming northwest 30 km/h late in the morning. High 24. UV index 7 or high. Friday night..A few clouds. Wind northwest 30 km/h becoming light near midnight. Wind becoming west 30 before morning. Low 17. Bracebridge - Gravenhurst. Tonight..A few clouds. Low 9. Friday..Sunny. Becoming a mix of sun and cloud in the afternoon. High 25. UV index 8 or very high. Friday night..Partly cloudy. Becoming clear before morning. Low 9. Town of Parry Sound - Rosseau - Killbear Park. Tonight..Clear. Wind north 30 km/h becoming light late this evening. Low 12. Friday..Sunny. Becoming a mix of sun and cloud late in the morning. Wind becoming west 30 km/h late in the morning. High 23. Humidex 26. UV index 7 or high. Friday night..Clear. Becoming partly cloudy late in the evening. Wind northwest 30 km/h becoming light in the evening. Wind becoming west 30 after midnight. Low 12. Huntsville - Baysville. Tonight..Partly cloudy. Clearing this evening. Low 12. Friday..Sunny. Becoming a mix of sun and cloud late in the morning. Wind becoming north 20 km/h late in the morning. High 23. Humidex 26. UV index 7 or high. Friday night..Partly cloudy. Low 12. Haliburton - Minden - Southern Haliburton County. Tonight..Partly cloudy. Low 10. Friday..Sunny. Becoming a mix of sun and cloud in the afternoon. High 22. UV index 8 or very high. Friday night..A few clouds. Low 9. Oxtongue Lake - Fort Irwin - Northern Haliburton County. Tonight..Partly cloudy. Low 10. Friday..Sunny. Becoming a mix of sun and cloud near noon. Wind becoming north 20 km/h late in the morning. High 22. UV index 8 or very high. Friday night..A few clouds. Low 9. Barry's Bay - Killaloe. Tonight..Mainly cloudy. Clearing late this evening. Low 11. Friday..Sunny. Becoming a mix of sun and cloud in the afternoon. Wind becoming northwest 20 km/h late in the morning. High 23. UV index 7 or high. Friday night..A few clouds. Low 12. Renfrew - Arnprior - Calabogie. Tonight..Mainly cloudy. Clearing late this evening. Low 11. Friday..Sunny. Wind becoming north 20 km/h late in the morning. High 23. UV index 7 or high. Friday night..A few clouds. Low 12. Petawawa - Pembroke - Cobden. Tonight..Mainly cloudy. Clearing this evening. Wind becoming northeast 30 km/h this evening then light after midnight. Low 11. Friday..Sunny. Becoming a mix of sun and cloud in the afternoon. Wind becoming northwest 20 km/h late in the morning. High 23. UV index 7 or high. Friday night..Partly cloudy. Low 12. Western Algonquin Park - Lake of Two Rivers. Tonight..Mainly cloudy. Clearing this evening. Low 7. Friday..Sunny. Becoming a mix of sun and cloud late in the morning. High 22. UV index 7 or high. Friday night..A few clouds. Low 9. Deep River - Whitney - Eastern Algonquin Park. Tonight..Mainly cloudy. Clearing this evening. Low 7. Friday..Sunny. Becoming a mix of sun and cloud near noon. High 22. UV index 7 or high. Friday night..Partly cloudy. Low 9. Bayfield Inlet - Dunchurch. Tonight..Partly cloudy. Clearing this evening. Low 11. Friday..Sunny. Becoming a mix of sun and cloud in the morning. High 24. Humidex 25. UV index 7 or high. Friday night..Partly cloudy. Low 13. South River - Burk's Falls. Tonight..Partly cloudy. Clearing this evening. Low 11. Friday..Sunny. Becoming a mix of sun and cloud in the morning. High 24. Humidex 25. UV index 7 or high. Friday night..Partly cloudy. Low 13. End $$$$^^ --- up 4 hours, 19 minutes * Origin: Northern Realms (1:229/664) .