Subj : Southern Ontario Weather To : All From : Northern Realms Date : Tue Sep 30 2025 11:05:00 FPCN11 CWTO 301500 Forecasts for Southern Ontario and the National Capital Region issued by Environment Canada at 11:00 a.m. EDT Tuesday 30 September 2025 for today and Wednesday. The next scheduled forecast will be issued at 3:30 p.m. EDT. City of Toronto. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low 8. Wednesday..Sunny. Wind becoming east 20 km/h near noon. High 17. UV index 6 or high. Windsor - Leamington - Essex County. Today..Sunny. High 26. Humidex 28. Tonight..Clear. Wind becoming northeast 20 km/h near midnight. Low 9. Wednesday..Sunny. Wind east 20 km/h gusting to 40. High 21. UV index 6 or high. Chatham-Kent - Rondeau Park. Today..Sunny. High 24. Humidex 26. Tonight..Clear. Wind becoming east 20 km/h near midnight. Low 7. Wednesday..Sunny. Wind east 20 km/h gusting to 40. High 20. UV index 6 or high. Sarnia - Petrolia - Western Lambton County. Today..Sunny. High 24. Humidex 26. Tonight..Clear. Wind becoming east 20 km/h near midnight. Low 7. Wednesday..Sunny. Wind east 20 km/h gusting to 40. High 20. UV index 6 or high. Watford - Pinery Park - Eastern Lambton County. Today..Sunny. High 24. Humidex 26. Tonight..Clear. Wind becoming east 20 km/h near midnight. Low 7. Wednesday..Sunny. Wind east 20 km/h gusting to 40. High 20. UV index 6 or high. Rodney - Shedden - Western Elgin County. Today..Sunny. High 24. Humidex 26. Tonight..Clear. Wind becoming east 20 km/h near midnight. Low 7. Wednesday..Sunny. Wind east 20 km/h gusting to 40. High 20. UV index 6 or high. St. Thomas - Aylmer - Eastern Elgin County. Today..Sunny. High 24. Humidex 26. Tonight..Clear. Wind becoming east 20 km/h near midnight. Low 7. Wednesday..Sunny. Wind east 20 km/h gusting to 40. High 20. UV index 6 or high. Strathroy - Komoka - Western Middlesex County. Today..Sunny. High 24. Humidex 26. Tonight..Clear. Wind becoming east 20 km/h near midnight. Low 7. Wednesday..Sunny. Wind east 20 km/h gusting to 40. High 20. UV index 6 or high. London - Parkhill - Eastern Middlesex County. Today..Sunny. High 24. Humidex 26. Tonight..Clear. Wind becoming east 20 km/h near midnight. Low 7. Wednesday..Sunny. Wind east 20 km/h gusting to 40. High 20. UV index 6 or high. Simcoe - Delhi - Norfolk. Today..Sunny. Wind northeast 20 km/h. High 23. Humidex 25. Tonight..Clear. Wind northeast 20 km/h. Low plus 5. Wednesday..Sunny. Wind northeast 20 km/h gusting to 40. High 19. UV index 6 or high. Dunnville - Caledonia - Haldimand. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Wind northeast 20 km/h. Low 7. Wednesday..Sunny. Wind northeast 20 km/h gusting to 40. High 17. UV index 6 or high. Woodstock - Tillsonburg - Oxford County. Today..Sunny. Wind northeast 20 km/h. High 23. Humidex 25. Tonight..Clear. Wind northeast 20 km/h. Low plus 5. Wednesday..Sunny. Wind northeast 20 km/h gusting to 40. High 19. UV index 6 or high. Brantford - County of Brant. Today..Sunny. Wind northeast 20 km/h. High 23. Humidex 25. Tonight..Clear. Wind northeast 20 km/h. Low plus 5. Wednesday..A mix of sun and cloud. Becoming sunny late in the morning. Wind northeast 20 km/h gusting to 40. High 19. UV index 6 or high. Niagara Falls - Welland - Southern Niagara Region. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Wind northeast 20 km/h. Low 9. Wednesday..A mix of sun and cloud. Becoming sunny in the morning. Wind northeast 20 km/h gusting to 40. High 16. UV index 6 or high. St. Catharines - Grimsby - Northern Niagara Region. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Wind northeast 20 km/h. Low 9. Wednesday..A mix of sun and cloud. Clearing late in the morning. Wind northeast 20 km/h gusting to 40. High 16. UV index 6 or high. City of Hamilton. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Wind northeast 20 km/h. Low 9. Wednesday..A mix of sun and cloud. Becoming sunny late in the morning. Wind northeast 20 km/h gusting to 40. High 16. UV index 6 or high. Burlington - Oakville. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Wind northeast 20 km/h. Low 9. Wednesday..Mainly sunny. Wind northeast 20 km/h gusting to 40. High 16. UV index 6 or high. Halton Hills - Milton. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low 8. Wednesday..Sunny. Wind becoming east 20 km/h near noon. High 17. UV index 6 or high. Mississauga - Brampton. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low 8. Wednesday..Sunny. Wind becoming east 20 km/h near noon. High 17. UV index 6 or high. Caledon. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Vaughan - Richmond Hill - Markham. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low 8. Wednesday..Sunny. Wind becoming east 20 km/h near noon. High 17. UV index 6 or high. Newmarket - Georgina - Northern York Region. Today..Sunny. High 22. Tonight..Clear. Low plus 4. Wednesday..Sunny. High 17. UV index 6 or high. Pickering - Oshawa - Southern Durham Region. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low 8. Wednesday..Sunny. Wind becoming east 20 km/h near noon. High 17. UV index 6 or high. Uxbridge - Beaverton - Northern Durham Region. Today..Sunny. High 22. Tonight..Clear. Low plus 4. Wednesday..Sunny. High 17. UV index 6 or high. Goderich - Bluewater - Southern Huron County. Today..Sunny. Wind northeast 20 km/h. High 23. Humidex 25. Tonight..Clear. Low plus 4. Wednesday..Sunny. High 19. UV index 6 or high. Wingham - Blyth - Northern Huron County. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Stratford - Mitchell - Southern Perth County. Today..Sunny. Wind northeast 20 km/h. High 23. Humidex 25. Tonight..Clear. Low plus 4. Wednesday..Sunny. High 19. UV index 6 or high. Listowel - Milverton - Northern Perth County. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Kitchener - Cambridge - Region of Waterloo. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Guelph - Erin - Southern Wellington County. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Mount Forest - Arthur - Northern Wellington County. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Orangeville - Grand Valley - Southern Dufferin County. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Shelburne - Mansfield - Northern Dufferin County. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Innisfil - New Tecumseth - Angus. Today..Sunny. High 22. Tonight..Clear. Low plus 4. Wednesday..Sunny. High 17. UV index 6 or high. Saugeen Shores - Kincardine - Southern Bruce County. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Bruce Peninsula - Sauble Beach - Tobermory. Today..Sunny. Wind northeast 20 km/h gusting to 40. High 20. Tonight..Clear. Wind northeast 20 km/h gusting to 40. Low 6. Wednesday..Sunny. Wind east 20 km/h. High 16. UV index 5 or moderate. Hanover - Dundalk - Southern Grey County. Today..Sunny. Wind east 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 5 or moderate. Owen Sound - Blue Mountains - Northern Grey County. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 5 or moderate. Barrie - Collingwood - Hillsdale. Today..Sunny. High 22. Tonight..Clear. Low plus 4. Wednesday..Sunny. High 17. UV index 6 or high. Midland - Coldwater - Orr Lake. Today..Sunny. High 22. Tonight..Clear. Low plus 4. Wednesday..Sunny. High 17. UV index 6 or high. Orillia - Lagoon City - Washago. Today..Sunny. High 22. Tonight..Clear. Low plus 4. Wednesday..Sunny. High 17. UV index 6 or high. Cobourg - Colborne - Western Northumberland County. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Low plus 5. Wednesday..Sunny. High 17. UV index 6 or high. Belleville - Quinte West - Eastern Northumberland County. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Low plus 5. Wednesday..Sunny. High 17. UV index 6 or high. Picton - Sandbanks Park. Today..Sunny. Wind northeast 20 km/h. High 21. Tonight..Clear. Low plus 5. Wednesday..Sunny. High 17. UV index 6 or high. Napanee - Consecon. Today..Sunny. Wind northeast 20 km/h. High 21. Tonight..Clear. Low plus 5. Wednesday..Sunny. High 17. UV index 6 or high. Kingston - Odessa - Frontenac Islands. Today..Sunny. Wind northeast 20 km/h. High 22. Tonight..Clear. Low plus 5. Wednesday..Sunny. High 17. UV index 6 or high. Lindsay - Southern Kawartha Lakes. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 18. UV index 6 or high. Fenelon Falls - Balsam Lake Park - Northern Kawartha Lakes. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 18. UV index 6 or high. Peterborough City - Lakefield - Southern Peterborough County. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 18. UV index 6 or high. Apsley - Woodview - Northern Peterborough County. Today..Sunny. High 19. Tonight..Clear. Low plus 1 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Stirling - Tweed - Madoc. Today..Sunny. High 21. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Tamworth - Sydenham - South Frontenac. Today..Sunny. High 20. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Kaladar - Bannockburn - Bon Echo Park. Today..Sunny. High 19. Tonight..Clear. Low plus 1 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Bancroft - Hastings Highlands - Denbigh. Today..Sunny. High 19. Tonight..Clear. Low zero with frost. Wednesday..A mix of sun and cloud. Becoming sunny in the morning. High 15. UV index 6 or high. Gananoque - Mallorytown. Today..Sunny. High 21. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Brockville - Prescott. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Westport - Charleston Lake. Today..Sunny. High 20. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Merrickville-Wolford - Kemptville. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Ottawa North - Kanata - Orl‚ans. Today..Sunny. High 21. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 17. UV index 6 or high. Ottawa South - Richmond - Metcalfe. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Gatineau. Today..Sunny. High 21. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 17. UV index 6 or high. Prescott and Russell. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Morrisburg - Long Sault. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Mainly sunny. High 17. UV index 6 or high. Cornwall - Lancaster. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..A mix of sun and cloud. Becoming sunny near noon. High 17. UV index 6 or high. Winchester - Newington. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Maxville - Alexandria. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Plevna - Sharbot Lake - Western Lanark County. Today..Sunny. High 19. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Smiths Falls - Perth - Eastern Lanark County. Today..Sunny. High 20. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Port Carling - Port Severn. Today..Sunny. High 19. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Bracebridge - Gravenhurst. Today..Sunny. High 21. Tonight..Clear. Low plus 2 with patchy frost. Wednesday..Sunny. High 18. UV index 6 or high. Town of Parry Sound - Rosseau - Killbear Park. Today..Sunny. High 19. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 6 or high. Huntsville - Baysville. Today..Sunny. High 17. Tonight..Clear. Low zero with frost. Wednesday..Sunny. High 15. UV index 6 or high. Haliburton - Minden - Southern Haliburton County. Today..Sunny. High 18. Tonight..Clear. Low zero with frost. Wednesday..Sunny. High 15. UV index 6 or high. Oxtongue Lake - Fort Irwin - Northern Haliburton County. Today..Sunny. High 17. Tonight..Clear. Low zero with frost. Wednesday..Sunny. High 15. UV index 6 or high. Barry's Bay - Killaloe. Today..Sunny. High 17. Tonight..Clear. Low zero with frost. Wednesday..A mix of sun and cloud. Becoming sunny in the morning. High 15. UV index 6 or high. Renfrew - Arnprior - Calabogie. Today..Sunny. High 19. Tonight..Clear. Low plus 1 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Petawawa - Pembroke - Cobden. Today..Sunny. High 19. Tonight..Clear. Low plus 1 with patchy frost. Wednesday..Sunny. High 17. UV index 6 or high. Western Algonquin Park - Lake of Two Rivers. Today..Sunny. High 17. Tonight..Clear. Low zero with frost. Wednesday..Sunny. High 15. UV index 6 or high. Deep River - Whitney - Eastern Algonquin Park. Today..Sunny. High 17. Tonight..Clear. Low zero with frost. Wednesday..A mix of sun and cloud. Becoming sunny in the morning. High 15. UV index 6 or high. Bayfield Inlet - Dunchurch. Today..Sunny. High 19. Tonight..Clear. Low plus 3 with risk of frost. Wednesday..Sunny. High 18. UV index 5 or moderate. South River - Burk's Falls. Today..Sunny. High 17. Tonight..Clear. Low zero with frost. Wednesday..Sunny. High 15. UV index 5 or moderate. End $$$$^^ --- up 2 days, 2 hours, 48 minutes * Origin: Northern Realms (618:400/23) .