How to read a weather forecast

A forecast is a few numbers and a few words. This guide explains what each one means so you can plan a day around it.

The current temperature

The large number at the top of a weather app is the air temperature now, measured in the shade. It is the number most people check first, and it is the one Bold Weather makes largest.

The high and the low

The high is the warmest the day is expected to get, usually in the afternoon. The low is the coldest, usually just before sunrise. On a daily list, the low shown for a day is often the overnight low that follows it. If you are planning an early walk, the low matters more than the high.

Feels like

The feels-like temperature adjusts the air temperature for wind and humidity. On a cold, windy day it is lower than the air temperature. On a hot, humid day it is higher. The feels like and wind chill guide explains the two calculations.

The chance of rain

A 40 percent chance of rain means that, at any point in the forecast area, there is a 40 percent chance of measurable rain during the forecast period. It does not mean that 40 percent of the area will be wet, or that it will rain for 40 percent of the time. The National Weather Service explains the calculation in its probability of precipitation page.

A useful way to read it is in words. Under about 30 percent, rain is unlikely. Between 30 and 60 percent, rain is possible and worth a coat in the car. Above 60 percent, rain is likely. Bold Weather shows the number and those words together.

Hourly and daily forecasts

An hourly forecast shows the next day or so hour by hour. It is the one to read when planning the next few hours. A daily forecast shows each of the next several days with a high, a low, and a description. It is the one to read when planning a week. The two can look different for the same day because the daily view summarizes a whole day.

Sunrise and sunset

Sunrise and sunset times tell you how much daylight you have. They change a little every day and by several minutes a week near the spring and autumn.

Wind

Wind is given as a speed and a direction. The direction is where the wind comes from, so a west wind blows from the west toward the east. Gusts are short bursts stronger than the steady wind.

What this means for Bold Weather

Bold Weather shows the temperature, the high and low, the feels-like temperature, and the chance of rain first, in large type, with a sentence that puts them together. Explore the plain-language forecast or learn about the TestFlight beta.