A forecast gives you temperatures and millimetres. What you actually want to know is more practical: what time to open the windows without making the living room damp, whether the washing will dry outside before evening, when to put on sunscreen, whether the plants need bringing in tonight. This section answers those questions in Canada with 9 everyday indicators, recalculated every time the forecasts are updated.
Every town or place page on the site shows, under the heading, a “Today in…” box that includes only the indicators that have something to say that day, with the time slot and the values for that location. The pages below explain where each piece of advice comes from: the physics involved, how to read the indicator, the thresholds used, a worked example and the limits of the method.
The indicators, one by one
- Air the house without adding damp: best timeThe time slot when outdoor air dries the house, and the dust mite risk.
- Drying washing outside: how long will it take?The slot for hanging washing outside and the estimated drying time.
- UV index: when to seek shade, and time to sunburnThe peak UV index, the hours in the shade and the time to sunburn.
- Heatwaves and tropical nights: ventilating at nightThe hot days, the tropical nights and the time to ventilate.
- Frost and plants: what time, how coldThe low, the time of the frost and what to protect.
- Watering the garden: water or wait?Water or wait: a two-day balance of rain and evapotranspiration.
- Terrace and barbecue: the evening at a glanceThe evening from 18:00 to 22:00: rain, wind, temperature.
- Starry sky: cloud and moon tonightTonight's cloud cover and the phase of the moon.
- Snow and black ice: road conditionsThe snow expected, the likely black ice and the ground temperature.
Where the numbers come from
The calculations start from Open-Meteo forecasts for the exact point of each town: temperature, dew point, wind and gusts, rain and probability of rain, cloud cover, UV index, snowfall, ground temperature and evapotranspiration. These are model values, not sensor readings, and they are refreshed several times a day.
An indicator with nothing to say stays silent: you will never see a list of “nothing to report”. The thresholds are written once, in the site's code, and reproduced as they are on each explanatory page, so that the advice shown and the published rule can never drift apart.
The pollen indicator is not available here: the European air quality model that supplies the concentrations does not cover this country, and we would rather leave the indicator out than make one up.
The Weather Atlas: understanding the sky
The everyday advice above rests on a few basic ideas: clouds, pressure, humidity, precipitation and wind. The Atlas explains each one, with a drawing for every cloud genus, charts, and a worked example based on today's forecast. Open the Weather Atlas