Eating outside comes down to very little: no shower, a wind that does not blow the barbecue out and a temperature that does not drive you indoors before dessert. A whole-day forecast does not tell you that, because the evening is nothing like the afternoon: the sun sinks, the air cools quickly, the wind drops or picks up.
Why this indicator matters
Temperature matters more than you might think. Below 16 °C, you look for a jacket; below 12 °C, you do not linger; below 5 °C, it is no longer a terrace. Wind affects comfort long before safety: at 25 km/h, napkins fly away and the smoke follows you around.
Evening rain is the most treacherous: a summer thunderstorm is often born in late afternoon and breaks between 19:00 and 21:00. The hour's probability of rain, combined with the forecast total, lets you keep plan B within reach rather than discovering the shower at dessert.
How to read it
The box sums up the evening from 18:00 to 22:00 (tomorrow's, after 22:00) in a single verdict: rain likely, wind a nuisance, too cool, too cold to eat outside, or a good evening. It gives the values behind the verdict: temperature at 20:00, average wind and gusts, probability of rain.
When the evening is fine but the air is cooling, the sentence gives the time at which the temperature falls below 16 °C: the moment to switch on the patio heater or bring out the blankets.
The thresholds used on this site
Every sentence in the “Today” box comes from a numerical rule. Here are the rules for this indicator, exactly as they are applied in the code.
- Evening taken into account: from 18:00 to 22:00.
- Rain likely: at least 0.2 mm over the evening, or a probability of at least 50 %.
- Wind a nuisance: 25 km/h on average, or gusts of at least 45 km/h.
- Temperature at 20:00: below 5 °C, too cold to eat outside; below 12 °C, cool; the air turns cool below 16 °C.
A worked example: Toronto
In Toronto, with the forecasts of 2026-11-02 08:13: Terrace and barbecue between 18:00 and 23:00: dry, wind at 7 km/h, 14 °C at 8 pm. A lovely evening.
Its limits
A shelter, a south-facing wall or a patio heater changes how it feels a great deal: the temperature given is that of open air. Wind at ten metres height is not that of an enclosed courtyard. Finally, the verdict says nothing about humidity or midges, which can spoil a perfect evening.
Frequently asked questions
Why the evening rather than the whole day?
Because that is when people eat outside and the barbecue is going. A fine day can end in a thunderstorm or at 10 °C, and the other way round.
At what wind speed should I give up on the barbecue?
Around 25 km/h on average, the embers glow unevenly and the smoke becomes a nuisance; from gusts of 45 km/h, you should also put the parasol away.
Does the probability of rain tell you how much water to expect?
No: it tells you the chance of rain at that hour. A 50 % probability with a total of 0.1 mm means a brief spot of rain, the same probability with 5 mm a proper shower.