PALO ALTO WEATHER.com

Weather & Air Quality History

Weather • Air Quality • Seismic Activity


Graphs Year

last 365 days

Pick a measureSep 15, 2026

Air qualityAQI against the EPA categories

29 Good
GoodModerateSensitiveUnhealthyVery unhealthy0100200300SepOctNovDecJanFebMarAprMayJunJulAug

High 200 Sep 23, 2025Low 0 Sep 18, 2025

Air quality indexEPA categories

The year at a glancelast 365 days

TEMPERATURE & DEW POINT °F0.025.050.075.0100.0125.0high 100.2°F Jun 11, 2026low 31.5°F Jan 10, 2026HUMIDITY050100WIND mph & DIRECTION0102030RAIN in0.005.00BAROMETER inHg29.00030.00031.000SOLAR W/m² (pale = clear-sky maximum)0200400AIR QUALITY INDEX0200400CARBON DIOXIDE ppm05001000SepOctNovDecJanFebMarAprMayJunJulAug

High 100.2°F Jun 11, 2026Low 31.5°F Jan 10, 2026

TemperatureDew point

Drag across the frame to read every panel at the same moment. A panel’s label jumps to that measure at full size.

Humiditywith dew point

78%
0.020.040.060.080.0dew °F050100SepOctNovDecJanFebMarAprMayJunJulAug

High 97% Nov 21, 2025Low 15% Mar 28, 2026

HumidityDew point, right scale

Windspeed and gusts; arrows fly the way the wind is blowing

1 mph NNE
0102030SepOctNovDecJanFebMarAprMayJunJulAug

Peak gust 27 mph Dec 25, 2025Now from NNE

WindGustArrows fly with the wind

Rain7-day totals

14.73 in
0.001.002.003.00OctNovDecJanFebMarAprMayJunJulAug

Total 14.73 inWettest 2.83 in Feb 19, 2026

Barometerlast 365 days

29.881 inHg
29.00029.50030.00030.50031.000SepOctNovDecJanFebMarAprMayJunJulAug

High 30.526 inHg Jan 10, 2026Low 29.481 inHg Dec 24, 2025

Sunmeasured against the clear-sky maximum, in pale

265 W/m²
0.05.010.015.0UV0200400SepOctNovDecJanFebMarAprMayJunJulAug

Peak 1187 W/m² May 25, 2026Peak UV 12.1 Jul 20, 2026Of clear sky 76%

MeasuredClear-sky maximumUV, right scale

Air qualityAQI against the EPA categories

29 Good
GoodModerateSensitiveUnhealthyVery unhealthy0100200300SepOctNovDecJanFebMarAprMayJunJulAug

High 200 Sep 23, 2025Low 0 Sep 18, 2025

Air quality indexEPA categories

Carbon dioxidelast 365 days

415 ppm
02505007501000SepOctNovDecJanFebMarAprMayJunJulAug

High 861 ppm Jan 13, 2026Low 154 ppm Aug 10, 2026

Carbon dioxideOutdoor background, 425 ppm

Stationsignal and console battery

99%
0%50%100%3.84.04.2SepOctNovDecJanFebMarAprMayJunJulAug

Signal now 99%Battery 3.9 V

SignalBattery, right scale

Go to Top