Pick your city or town and see whether today and the next few days are good for mowing, watering, sod, seeding, fertilizing, polymeric sand, sealing, planting, or salting the driveway.
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Ratings are general guidance based on the Environment and Climate Change Canada forecast for the nearest forecast location, not a guarantee. Always follow the label on fertilizer, seed, polymeric sand or sealer. Contains information licensed under the Open Government Licence – Canada.
What the ratings mean
- Good: the forecast suits the job.
- OK: doable with care; the note says what to watch.
- Wait: rain, cold, heat or frost is likely to spoil the job.
- Skip: not needed, for example watering before a rainy day.
The tool reads Environment Canada's latest city forecast (daytime highs, overnight lows, the chance and amount of rain or snow, and the next 24 hours hour by hour) and applies the rules below. It updates whenever Environment Canada does, several times a day.
Can I cut grass today?
Mow when the grass is dry. Wet grass clumps, tears instead of cutting cleanly and can rut soft ground, so after rain wait until the blades are dry, usually a few hours, and avoid early-morning dew. Keep most Ontario lawns at about 3 inches and never take more than a third of the height at once. Below roughly 5°C the lawn stops growing and doesn't need cutting.
Should I water my lawn today?
Skip it if rain is likely today or tonight. On hot, dry days water deeply in the early morning so less is lost to evaporation and the grass is dry by night. Most established lawns need about 2.5 cm (1 inch) of water a week, rain included. In cool weather lawns need very little.
Is it too cold to lay sod or grass seed?
Sod can go down any time the ground isn't frozen, including October in southern Ontario, because it arrives already grown; cool, damp weather actually helps it root. Grass seed is different: it needs warm soil to germinate, so daytime highs around 15–25°C are ideal and cold nights below a few degrees stall it. That's why late August to September is the best overseeding window in the GTA.
When to overseed and fertilize a lawn in Ontario
Overseed in late summer to early fall, or in spring with steady watering. Fertilize while the lawn is actively growing: late spring, and again from late summer into fall. Avoid feeding in heat waves, when it can scorch, and when it's too cold for the grass to use it. A light rain soon after spreading helps water fertilizer in; a downpour can wash it away.
Polymeric sand and rain
Polymeric sand hardens between pavers after it's wetted, and most products need a dry window afterwards (often around 24 hours) plus above-freezing temperatures while it sets. Rain too soon can wash it out of the joints or leave a haze on the pavers. The tool rates a day Good only when today and tonight look dry and no frost is expected. Some newer products are more rain-tolerant, so always check the bag.
Best temperature to seal a driveway
Most driveway and paver sealers need about 10°C and rising, sunshine, and a dry day or two to cure, so cool or showery days are rated Wait. Late spring and summer are usually the easiest time to seal in Ontario.
Salt the driveway before snow or freezing rain?
Yes. Salting before a storm stops ice bonding to the surface, so it shovels or plows off more easily. The tool flags nights where temperatures drop near or below freezing with snow, freezing rain or wet surfaces forecast. Interlock handles salt well; just avoid piling salty snow onto lawns and garden beds.
Planning a bigger project? Try the interlock driveway cost calculator, read about sod installation and lawn care, or text photos to 437-299-1681.
Questions about this tool
Can I cut grass after rain?
Yes, once the grass blades are dry, usually a few hours after the rain stops. Mowing wet grass clumps, tears the blades and can rut soft soil.
Should I water my lawn before rain?
No. If rain is likely today or tonight, skip watering and let the rain do it.
Is it too cold to lay sod in October?
Usually not in southern Ontario. Sod can be laid any time the ground isn't frozen, and cool, damp fall weather helps it root.
What temperature is too cold for grass seed?
Seed germinates poorly when daytime highs fall below about 10°C or nights get near freezing. Highs of 15–25°C are ideal.
When should I overseed my lawn in Ontario?
Late August to September is the best window in the GTA and southern Ontario. Spring works too with regular watering.
When should I fertilize my lawn in Ontario?
While it's actively growing: late spring, and again from late summer into fall. Avoid heat waves and very cold weather.
How long does polymeric sand need without rain?
Most products need a dry window after installation, often around 24 hours, and above-freezing temperatures. Follow the instructions on your product.
What temperature do you need to seal a driveway?
Most sealers need about 10°C and rising, with dry weather for a day or two to cure.
Should I salt my driveway before it snows?
Yes. Pre-salting before snow or freezing rain stops ice from bonding to the surface, so it's easier to clear.
Where does the forecast come from?
From Environment and Climate Change Canada's official city forecasts, read live in your browser. The yard-work ratings are our guidance on top of that forecast.