United States · 1991–2020 normal
Portola Valley in
September.
Typical September weather in Portola Valley: 30.6°C by day, 10.2°C at night, 2 mm of rain over 0.4 wet days. These are measured 1991–2020 station normals, not a forecast.
Typical high30.6°C
Typical low10.2°C
Rain2 mm
Wet days0.4
Comfort score 70 this month (May leads the year at 81). Daylight is calculated as 12 h 23 from latitude 37.38°. Open-water sea temperature is 14.9°C (12 km from the place centre).
The evidence behind this page
One month,
from the same station.
- Place identity
- GeoNames 5384478
- NOAA station
- USC00049792 · WOODSIDE FIRE STN 1
- Station distance
- 5.3 km from the place centre
- Coverage
- Good coverage · 22 usable years
- Important limit
- Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.