How to read a weather forecast
A forecast is a set of probabilities and estimates. Knowing what each number means helps you plan better and worry less.
Chance of rain is not how much rain
A 40% chance of rain means that, in similar conditions, rain would be measurable at that place about four times out of ten. It does not tell you how heavy the rain will be or how long it will last. Look at the expected amount (in millimetres) and the hourly timing as well: a 70% chance of a light shower for one hour is a very different day from a 70% chance of steady rain all afternoon.
“Feels like” temperature
The feels-like value combines air temperature with wind and humidity to estimate how the weather feels on the body. In cold, windy weather it is lower than the air temperature (wind chill). In hot, humid weather it is higher (heat index), because sweat evaporates more slowly. Use feels-like to decide what to wear and how hard to exert yourself, and the air temperature for things like frost on plants or road ice.
Wind speed and gusts
Wind speed is the average over a short period, while gusts are brief peaks that can be much stronger. Gusts matter for cycling, boating, cranes, tents, drones and driving high-sided vehicles. As a rough guide, sustained winds above about 40 km/h make walking and cycling hard, and gusts above about 60 km/h can break branches and cause damage.
Humidity and comfort
High humidity makes warm weather feel hotter and slows cooling by sweat, so heat is more dangerous on a humid day than on a dry day at the same temperature. Very low humidity dries skin and eyes and raises wildfire risk. Dew point (the temperature at which air becomes saturated) is the most reliable comfort guide: above about 20 °C most people feel muggy.
Use the hourly view for same-day plans
The daily summary shows a high, a low and a headline. The hourly view shows when rain starts and stops, when wind peaks and when the heat is greatest. For walking, errands, outdoor work and events, find the best window in the hourly view instead of judging the whole day by its worst hour.
How far ahead can you trust it?
Forecasts are most reliable in the next 24 to 48 hours and become less certain each day after that. Temperature is usually more reliable than rain timing, and local thunderstorms are the hardest thing to predict. Check again before an important plan, and always follow official warnings when they are issued.
Limits
This guide is general information, not a forecast or a safety warning. Local terrain, coasts, cities and mountains can make conditions differ from a regional forecast. For safety-critical decisions, rely on your national weather authority and local guidance.