Subj : Southern Ontario Weather To : All From : Northern Realms Date : Wed Oct 01 2025 15:35:00 FPCN11 CWTO 011930 Forecasts for Southern Ontario and the National Capital Region issued by Environment Canada at 3:30 p.m. EDT Wednesday 1 October 2025 for tonight Thursday and Thursday night. The next scheduled forecast will be issued at 5:00 a.m. EDT Thursday. City of Toronto. Tonight..Clear. Low 9. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..A few clouds. Low 11. Windsor - Leamington - Essex County. Tonight..Clear. Low 11. Thursday..Mainly sunny. High 23. Humidex 25. UV index 6 or high. Thursday night..A few clouds. Low 13. Chatham-Kent - Rondeau Park. Tonight..Clear. Low 8. Thursday..Mainly sunny. High 23. Humidex 25. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 13. Sarnia - Petrolia - Western Lambton County. Tonight..Clear. Low 8. Thursday..Mainly sunny. High 23. Humidex 25. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 9. Watford - Pinery Park - Eastern Lambton County. Tonight..Clear. Low 8. Thursday..Mainly sunny. High 23. Humidex 25. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 9. Rodney - Shedden - Western Elgin County. Tonight..Clear. Low 8. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 12. St. Thomas - Aylmer - Eastern Elgin County. Tonight..Clear. Low 8. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 12. Strathroy - Komoka - Western Middlesex County. Tonight..Clear. Low 8. Thursday..Mainly sunny. High 22. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 10. London - Parkhill - Eastern Middlesex County. Tonight..Clear. Low 8. Thursday..Mainly sunny. High 22. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 10. Simcoe - Delhi - Norfolk. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 22. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 9. Dunnville - Caledonia - Haldimand. Tonight..Clear. Low 7. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..A few clouds. Low 9. Woodstock - Tillsonburg - Oxford County. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 8. Brantford - County of Brant. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear after midnight. Low 8. Niagara Falls - Welland - Southern Niagara Region. Tonight..Clear. Low 9. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..A few clouds. Low 15. St. Catharines - Grimsby - Northern Niagara Region. Tonight..Clear. Low 9. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low 11. City of Hamilton. Tonight..Clear. Wind northeast 20 km/h becoming light early this evening. Low 9. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low 9. Burlington - Oakville. Tonight..Clear. Low 9. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..A few clouds. Low 7. Halton Hills - Milton. Tonight..Clear. Low 9. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..A few clouds. Low 7. Mississauga - Brampton. Tonight..Clear. Low 9. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..A few clouds. Low 7. Caledon. Tonight..Clear. Low plus 5. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..A few clouds. Low 7. Vaughan - Richmond Hill - Markham. Tonight..Clear. Low 9. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low 7. Newmarket - Georgina - Northern York Region. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low 7. Pickering - Oshawa - Southern Durham Region. Tonight..Clear. Low 9. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low 7. Uxbridge - Beaverton - Northern Durham Region. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low 7. Goderich - Bluewater - Southern Huron County. Tonight..Clear. Low 7. Thursday..Mainly sunny. High 23. UV index 6 or high. Thursday night..A few clouds. Low 8. Wingham - Blyth - Northern Huron County. Tonight..Clear. Low 7. Thursday..Mainly sunny. High 23. UV index 6 or high. Thursday night..A few clouds. Low 8. Stratford - Mitchell - Southern Perth County. Tonight..Clear. Low 7. Thursday..Mainly sunny. High 22. UV index 6 or high. Thursday night..A few clouds. Low 8. Listowel - Milverton - Northern Perth County. Tonight..Clear. Low 7. Thursday..Mainly sunny. High 22. UV index 6 or high. Thursday night..A few clouds. Low 8. Kitchener - Cambridge - Region of Waterloo. Tonight..Clear. Low plus 5. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..A few clouds. Low 7. Guelph - Erin - Southern Wellington County. Tonight..Clear. Low plus 5. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..A few clouds. Low 7. Mount Forest - Arthur - Northern Wellington County. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear near midnight. Low 7. Orangeville - Grand Valley - Southern Dufferin County. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear near midnight. Low plus 5. Shelburne - Mansfield - Northern Dufferin County. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear near midnight. Low plus 5. Innisfil - New Tecumseth - Angus. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low plus 5. Saugeen Shores - Kincardine - Southern Bruce County. Tonight..Clear. Low 7. Thursday..Mainly sunny. High 21. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear near midnight. Low 11. Bruce Peninsula - Sauble Beach - Tobermory. Tonight..Clear. Low 8. Thursday..Mainly sunny. High 17. UV index 5 or moderate. Thursday night..Clear. Low 12. Hanover - Dundalk - Southern Grey County. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear near midnight. Low 10. Owen Sound - Blue Mountains - Northern Grey County. Tonight..Clear. Low 7. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..Partly cloudy. Becoming clear near midnight. Low 10. Barrie - Collingwood - Hillsdale. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low 8. Midland - Coldwater - Orr Lake. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low 8. Orillia - Lagoon City - Washago. Tonight..Clear. Low 6. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low 11. Cobourg - Colborne - Western Northumberland County. Tonight..Clear. Low plus 5. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 9. Belleville - Quinte West - Eastern Northumberland County. Tonight..Clear. Low plus 5. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 9. Picton - Sandbanks Park. Tonight..Clear. Low 7. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 9. Napanee - Consecon. Tonight..Clear. Low plus 5. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 9. Kingston - Odessa - Frontenac Islands. Tonight..Clear. Low plus 5. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 9. Lindsay - Southern Kawartha Lakes. Tonight..Clear. Low plus 3 with risk of frost. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 7. Fenelon Falls - Balsam Lake Park - Northern Kawartha Lakes. Tonight..Clear. Low plus 2 with risk of frost. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 7. Peterborough City - Lakefield - Southern Peterborough County. Tonight..Clear. Low plus 3 with risk of frost. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Fog patches developing before morning. Low plus 4. Apsley - Woodview - Northern Peterborough County. Tonight..Clear. Low plus 2 with risk of frost. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Fog patches developing before morning. Low plus 4. Stirling - Tweed - Madoc. Tonight..Clear. Low plus 3 with risk of frost. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low 6. Tamworth - Sydenham - South Frontenac. Tonight..Clear. Low plus 3 with risk of frost. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low 6. Kaladar - Bannockburn - Bon Echo Park. Tonight..Clear. Low plus 1. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low plus 5. Bancroft - Hastings Highlands - Denbigh. Tonight..Clear. Low plus 1. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low plus 3. Gananoque - Mallorytown. Tonight..Clear. Low plus 3 with risk of frost. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 7. Brockville - Prescott. Tonight..Clear. Low plus 2 with frost. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 7. Westport - Charleston Lake. Tonight..Clear. Low plus 3 with risk of frost. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 7. Merrickville-Wolford - Kemptville. Tonight..Clear. Low plus 2 with frost. Thursday..Mainly sunny. High 19. UV index 6 or high. Thursday night..A few clouds. Low 7. Ottawa North - Kanata - Orleans. Tonight..Clear. Low plus 2 with frost. Thursday..Mainly sunny. High 19. UV index 5 or moderate. Thursday night..Clear. Low 6. Ottawa South - Richmond - Metcalfe. Tonight..Clear. Low plus 2 with frost. Thursday..Mainly sunny. High 19. UV index 5 or moderate. Thursday night..A few clouds. Low 6. Gatineau. Tonight..Clear. Low plus 2 with frost. Thursday..Mainly sunny. High 20. UV index 5 or moderate. Thursday night..Clear. Low plus 4. Prescott and Russell. Tonight..Clear. Low plus 1 with frost. Thursday..Mainly sunny. High 18. UV index 5 or moderate. Thursday night..A few clouds. Low plus 5. Morrisburg - Long Sault. Tonight..Clear. Low plus 2 with risk of frost. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low 7. Cornwall - Lancaster. Tonight..Clear. Low plus 1 with frost. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low 7. Winchester - Newington. Tonight..Clear. Low plus 2 with risk of frost. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low 7. Maxville - Alexandria. Tonight..Clear. Low plus 1 with frost. Thursday..Mainly sunny. High 18. UV index 5 or moderate. Thursday night..A few clouds. Low 6 with temperature rising to 9 by morning. Plevna - Sharbot Lake - Western Lanark County. Tonight..Clear. Low plus 2 with risk of frost. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low 6. Smiths Falls - Perth - Eastern Lanark County. Tonight..Clear. Low plus 3 with risk of frost. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low 6. Port Carling - Port Severn. Tonight..A few clouds. Low plus 5. Thursday..Mainly sunny. High 20. UV index 5 or moderate. Thursday night..A few clouds. Low 10. Bracebridge - Gravenhurst. Tonight..A few clouds. Low plus 3. Thursday..Mainly sunny. High 20. UV index 6 or high. Thursday night..A few clouds. Low plus 5. Town of Parry Sound - Rosseau - Killbear Park. Tonight..A few clouds. Low plus 5. Thursday..Mainly sunny. High 19. UV index 5 or moderate. Thursday night..A few clouds. Low 7. Huntsville - Baysville. Tonight..A few clouds. Low plus 3. Thursday..Mainly sunny. High 19. UV index 5 or moderate. Thursday night..A few clouds. Low 7. Haliburton - Minden - Southern Haliburton County. Tonight..Clear. Low plus 1. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low 6. Oxtongue Lake - Fort Irwin - Northern Haliburton County. Tonight..Clear. Low plus 1. Thursday..Mainly sunny. High 18. UV index 6 or high. Thursday night..A few clouds. Low 6. Barry's Bay - Killaloe. Tonight..Clear. Low plus 1. Thursday..Mainly sunny. High 18. UV index 5 or moderate. Thursday night..A few clouds. Low 6. Renfrew - Arnprior - Calabogie. Tonight..Clear. Low plus 1. Thursday..Mainly sunny. High 18. UV index 5 or moderate. Thursday night..A few clouds. Low 6. Petawawa - Pembroke - Cobden. Tonight..Clear. Low plus 1. Thursday..Mainly sunny. High 18. UV index 5 or moderate. Thursday night..A few clouds. Low 6. Western Algonquin Park - Lake of Two Rivers. Tonight..Clear. Low plus 1. Thursday..Mainly sunny. High 18. UV index 5 or moderate. Thursday night..A few clouds. Low plus 3. Deep River - Whitney - Eastern Algonquin Park. Tonight..Clear. Low plus 1. Thursday..Mainly sunny. High 18. UV index 5 or moderate. Thursday night..A few clouds. Low plus 3. Bayfield Inlet - Dunchurch. Tonight..A few clouds. Low plus 5. Thursday..Mainly sunny. High 18. UV index 5 or moderate. Thursday night..A few clouds. Low 7. South River - Burk's Falls. Tonight..A few clouds. Low plus 3. Thursday..Mainly sunny. High 18. UV index 5 or moderate. Thursday night..A few clouds. Low 7. End $$$$^^ --- up 3 days, 7 hours, 18 minutes * Origin: Northern Realms (618:400/23) .