Precipitation
How much rain, drizzle or melted snow is forecast to fall on the section during the hour you pass through.
- APPLIES TO
- ALL DEVICES
- LEARN SHEET
- PRECIPITATION
- UPDATED
- 15 OCT 2026
What it measures
The amount of rain, drizzle or melted snow forecast to fall at this section during the hour you pass through, such as 0.04 in or 1.0 mm.
On iPhone, iPad, Mac and Android, when snow is forecast, a separate SNOW reading follows this one with the depth of snow for that hour, such as 0.8 in or 2.0 cm, and opens the same explanation. On the web, SNOW follows CHANCE OF PRECIPITATION in the section’s sheet. With no snow forecast, there is no SNOW reading.
On CarPlay and Android Auto, a section’s details give the chance of precipitation with this amount, such as 60% · 0.03 in. When snow is forecast, the depth of snow takes the amount’s place: 70% · 1.6 in snow.
Why it matters on the road
The amount barely matters; the temperature is everything. A trace at or below freezing is ice on the road — often hard to see, and on bridges first. Ten times as much above freezing is a wet road and a longer stopping distance. That is why this reading is marked against the thermometer rather than against itself.
How it is marked
The road will be wet.
Anything falling above 0°C · 32°F
It freezes where it lands.
Anything falling at or below 0°C · 32°F
The SNOW reading carries the same marks, judged by the same air temperature.
A mark describes this reading alone and does not change the section’s rating; see Severity.
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