Wednesday will bring varying conditions across the region, including showers for the GTA and Eastern Ontario, a mix of sun and cloud for Midwestern and Central Ontario, and sunny skies in Deep Southwestern Ontario.

Tuesday will be a slightly warmer day across the region, with no precipitation expected along with sunny skies. Frost Advisories are in effect for many areas tonight.

5:17 PM ET - A Frost Advisory is in place for much of Southern #Ontario. Central Ontario is not included as Frost Advisories end there earlier in the month, however frost is still likely. Ensure plants are covered up or brought inside to prevent damage as temperatures fall near 0ºC tonight.

Some more showers are expected Monday in portions of Central, Eastern and Southwestern Ontario. Otherwise, varying conditions of sun and cloud is expected. It will be a cooler day across the area.

**Widespread Frost Possible Tuesday Morning** We are monitoring low temperatures tomorrow night into Tuesday morning that may fall close to or below the freezing mark. If temperatures fall low enough for Frost, this will likely be the first widespread frost of the season.

Sunday will bring showers, heavy at times, to much of the region. Sun and clouds are expected in Southwestern Ontario, with the risk for isolated showers. Frost Advisories are in effect for portions of Eastern Ontario.

3:48 PM ET - Frost Advisory in effect for portions of Eastern Ontario. Temperatures are expected to fall to near the freezing mark tonight into Sunday morning. Damage to plants, trees, and crops is possible. Ensure plants are brought inside or covered up to prevent damage.

Friday will be a cooler day across the region, with a mix of sun and cloud for all areas. No humidity is expected. Rain and maybe some thunder is likely overnight into tomorrow morning. The rain is expected to clear out of the region by mid to late morning.

6:37 PM ET - RADAR UPDATE: Rain is expected to move across the area tonight, with some periods of heavier rain possible. Some thunder is possible as well. *Image courtesy of WeatherWise.

The month of October will begin with continued rain showers throughout the day on Thursday, with some breaks in the rain likely. It will be a more humid day across Southern Ontario with portions of Southwestern Ontario likely to see Humidex values in the low 30s.

Wednesday will bring showers to much of the region, which will be intermittent through the day. Showers may be heavy at times. A mix of sun and cloud is expected for Eastern Ontario. Some fog is possible again tomorrow morning across the region.

**School Bus Cancellations - September 29, 2026** Buses in All Zones for the Lambton Kent District School Board and St. Clair Catholic District School Board have been cancelled this morning due to fog. Buses in All Zones will run this afternoon. #ckont #ONwx

6:04 AM ET - Fog Advisory in effect for Chatham-Kent and Sarnia-Lambton. An area of dense fog has developed early this morning. As a result, visibility will be reduced to near zero in some locales. Visibility will improve later this morning as the dense fog dissipates.

Tuesday will bring a mix of sun and cloud to much of the region, with mainly sunny skies expected in Southwestern Ontario and along the Lake Huron shoreline. The day will likely begin with some fog for much of the region.

Monday will bring sun and clouds to much of the region, with some showers at times in portions of Central and Eastern Ontario.

Saturday will bring another dry day filled with sunshine across Southern Ontario. Temperatures into the 20s are expected. The calm and dry conditions are expected to continue through the weekend and into the first half of next week.

Friday will bring another sunshine filled day across the region. There will be some clouds around, but mainly upper level clouds, so the sun should be quite prominent. Frost Advisories are in place for portions of Central, Eastern and Midwestern Ontario tonight.

6:38 PM ET - Frost Advisory in effect for a good portion of Southern Ontario. Patchy frost is expected Friday morning. Damage to plants, trees, and crops is possible.

Thursday will bring another day of Fall temperatures and no humidity. Mainly sunny skies are forecasted across the region. Frost Advisories are in effect tonight once again for portions of Central and Eastern Ontario.

5:52 PM ET - Frost Advisory continues for portions of Central and Eastern #Ontario. Patchy frost will return Thursday morning. Frost may return to some areas Friday morning. Damage to plants, trees, and crops is possible.

Wednesday will bring varying conditions of sun and cloud to the region. While Central and Eastern Ontario are likely to see mainly sunny skies, more clouds are expected in Southwestern Ontario.

5:41 PM ET - Frost Advisory in effect for portions of Central and Eastern #Ontario. Patchy frost is likely in many regions again on Wednesday morning. Damage to plants, trees, and crops is possible.

Monday will bring sun and clouds to much of the region, with mainly cloudy skies expected in Southwestern Ontario. It will be a cooler day across Southern Ontario, bringing a very fall-like feel to the area. Humidity is not forecasted.

2:44 PM ET - Frost Advisory in effect for portions of Central and Eastern #Ontario. Freezing temperatures with frost are expected tonight. Patchy frost is expected early Monday morning as temperatures fall to near the freezing mark.

Sunday will bring continued rain to Southwestern Ontario and portions of Eastern Ontario. A mix of sun and cloud is expected elsewhere. Rain is expected to taper off for a period of time tonight before moving back in tomorrow morning.

Saturday will bring rain, heavy at times, to Southwestern Ontario. Showers are expected in Midwestern Ontario and the Golden Horseshoe. Elsewhere, a mix of sun and cloud is expected. It will be a cooler and more fall-like day across the region.

**Fall Equinox is Coming!** Fall will officially arrive next Tuesday, September 22 at 8:04 PM! That day, day and night are roughly equal in length. Following the Fall Equinox, nights gradually become longer and days become shorter. It will officially be Fall until Monday, December 21.

Thursday will bring some showers, heavy at times, to Southwestern Ontario during the morning hours. Some showers will be possible elsewhere during the day with a mix of sun and cloud.

Wednesday will bring a mix of sun and cloud to the region, with humid conditions expected in Southwestern Ontario. There will be a risk for showers at any time tomorrow across the region, but any showers are not anticipated to last very long.

7:09 PM ET - Frost Advisory in effect for portions of Eastern #Ontario. Patchy frost is expected tonight into Tuesday morning as temperatures drop to near the freezing mark. Damage to plants, trees, and crops is possible. Cover up plants, especially those in frost-prone areas.