Weather for Saint Helena, California
Current Weather
Humidity: 97%
Feels Like: 49.2°F
Wind: N 2.2 mph
Wind Gusts: 2.3 mph
Precipitation: 0 in
Cloud Cover: 100%
Visibility: 6 mi
UV Index: 2.3
Five Day Weather Forecast
Tue
H: 68°F
L: 42°F
Wed
H: 68°F
L: 41°F
Thu
H: 66°F
L: 48°F
Fri
H: 59°F
L: 44°F
Sat
H: 56°F
L: 38°F
Air Quality
Nitrogen Dioxide: 46.25 μg/m3
Sulphur Dioxide: 4.65 μg/m3
Ozone: 17 μg/m3
Astronomical
Sun Transit: 11:56 AM
Sunset: 4:50 PM
Daylight: 9 hrs 48 mins
Moon Transit: 4:30 PM
Moonset: 9:30 PM
Moon Phase: Waxing Crescent
Moon Illumination: 25.0%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM4:00 PM - 6:30 PM
Minor Periods
9:00 PM - 10:30 PM11:08 AM - 12:38 AM
Action Rating: 2 out of 5
Dense Fog Advisory issued November 25 at 3:38AM PST until November 25 at 11:00AM PST by NWS San Francisco CA
Effective: Tue November 25, 2025, 11:38 AM
Expires: Tue November 25, 2025, 7:00 PM
* WHAT...Visibility one quarter mile or less in dense fog. * WHERE...North Bay Interior Valleys. * WHEN...Until 11 AM PST this morning. * IMPACTS...Low visibility could make driving conditions hazardous. Limited visibility will result in hazardous driving conditions.
If driving, slow down, use your headlights, and leave plenty of distance ahead of you. If commuting, allow extra drive time to reach your destination safely.
Dense Fog Advisory issued November 25 at 8:47AM PST until November 25 at 11:00AM PST by NWS San Francisco CA
Effective: Tue November 25, 2025, 4:47 PM
Expires: Tue November 25, 2025, 7:00 PM
* WHAT...Visibility one quarter mile or less in dense fog. * WHERE...North Bay Interior Valleys. * WHEN...Until 11 AM PST this morning. * IMPACTS...Low visibility could make driving conditions hazardous. Limited visibility will result in hazardous driving conditions.
If driving, slow down, use your headlights, and leave plenty of distance ahead of you. If commuting, allow extra drive time to reach your destination safely.
Dense Fog Advisory issued November 24 at 2:01PM PST until November 25 at 11:00AM PST by NWS Sacramento CA
Effective: Mon November 24, 2025, 10:01 PM
Expires: Tue November 25, 2025, 7:00 PM
* WHAT...Visibility one quarter mile or less in dense fog. * WHERE...Carquinez Strait and Delta, Central Sacramento Valley, Northern San Joaquin Valley, and Southern Sacramento Valley. * WHEN...From midnight tonight to 11 AM PST Tuesday. * IMPACTS...Low visibility could make driving conditions hazardous.
If driving, slow down, use your headlights, and leave plenty of distance ahead of you.
Freeze Warning issued November 25 at 4:05AM PST until November 25 at 9:00AM PST by NWS Eureka CA
Effective: Tue November 25, 2025, 12:05 PM
Expires: Tue November 25, 2025, 5:00 PM
* WHAT...Sub-freezing temperatures as low as 28 expected. * WHERE...Northeastern Mendocino Interior, Northern Lake, and Southern Trinity. * WHEN...Until 9 AM PST this morning. * IMPACTS...Frost and freeze conditions could kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing.
Take steps now to protect tender plants from the cold.
Frost Advisory issued November 25 at 4:05AM PST until November 25 at 9:00AM PST by NWS Eureka CA
Effective: Tue November 25, 2025, 12:05 PM
Expires: Tue November 25, 2025, 5:00 PM
* WHAT...Temperatures as low as 34 will result in frost formation. * WHERE...Southern Lake. * WHEN...Until 9 AM PST this morning. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.
Take steps now to protect tender plants from the cold.
Weather Forecast
Average Temperature: 51.9°F
Average Humidity: 64%
Wind: 3.8 mph
UV Index: 0.5
Air Quality
Nitrogen Dioxide: 21.97 μg/m3
Sulphur Dioxide: 3.13 μg/m3
Ozone: 35.56 μg/m3
Astronomical
Sun Transit: 11:56 AM
Sunset: 4:50 PM
Daylight: 9 hrs 48 mins
Moon Transit: 4:30 PM
Moonset: 9:30 PM
Moon Phase: Waxing Crescent
Moon Illumination: 25.0%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM4:00 PM - 6:30 PM
Minor Periods
9:00 PM - 10:30 PM11:08 AM - 12:38 AM
Action Rating: 2 out of 5
Weather Forecast
Average Temperature: 52.8°F
Average Humidity: 63%
Wind: 3.6 mph
UV Index: 0.5
Air Quality
Nitrogen Dioxide: 21.68 μg/m3
Sulphur Dioxide: 3.45 μg/m3
Ozone: 39.36 μg/m3
Astronomical
Sun Transit: 11:56 AM
Sunset: 4:50 PM
Daylight: 9 hrs 46 mins
Moon Transit: 5:18 PM
Moonset: 10:36 PM
Moon Phase: First Quarter
Moon Illumination: 35.3%
Best Times for Fishing or Hunting
Major Periods
12:00 AM - 12:00 AM4:48 PM - 7:18 PM
Minor Periods
10:06 PM - 11:36 PM11:39 AM - 1:09 PM
Action Rating: 3 out of 5
Weather Forecast
Average Temperature: 53.7°F
Average Humidity: 56%
Wind: 2.2 mph
UV Index: 0.5
Air Quality
Nitrogen Dioxide: 24.18 μg/m3
Sulphur Dioxide: 4.01 μg/m3
Ozone: 42.48 μg/m3
Astronomical
Sun Transit: 11:57 AM
Sunset: 4:50 PM
Daylight: 9 hrs 45 mins
Moon Transit: 6:03 PM
Moonset: 11:42 PM
Moon Phase: First Quarter
Moon Illumination: 46.5%
Best Times for Fishing or Hunting
Major Periods
12:43 AM - 3:13 AM5:33 PM - 8:03 PM
Minor Periods
12:00 AM - 12:00 AM12:05 AM - 1:35 PM
Action Rating: 2 out of 5
Weather Forecast
Average Temperature: 50.5°F
Average Humidity: 68%
Wind: 4.9 mph
UV Index: 0.4
Air Quality
Nitrogen Dioxide: 24.6 μg/m3
Sulphur Dioxide: 3.46 μg/m3
Ozone: 33.96 μg/m3
Astronomical
Sun Transit: 11:57 AM
Sunset: 4:49 PM
Daylight: 9 hrs 44 mins
Moon Transit: 6:49 PM
Moonset: 12:42 AM
Moon Phase: First Quarter
Moon Illumination: 57.8%
Best Times for Fishing or Hunting
Major Periods
1:30 AM - 4:00 AM6:19 PM - 8:49 PM
Minor Periods
12:30 AM - 2:00 PM12:00 AM - 12:00 AM
Action Rating: 2 out of 5
Weather Forecast
Average Temperature: 45.9°F
Average Humidity: 74%
Wind: 6.3 mph
UV Index: 0
Air Quality
Nitrogen Dioxide: 35.17 μg/m3
Sulphur Dioxide: 3.47 μg/m3
Ozone: 18.69 μg/m3
Astronomical
Sun Transit: 11:57 AM
Sunset: 4:49 PM
Daylight: 9 hrs 42 mins
Moon Transit: 6:12 PM
Moonset: 12:49 AM
Moon Phase: First Quarter
Moon Illumination: 68.7%
Best Times for Fishing or Hunting
Major Periods
2:14 AM - 4:44 AM5:42 PM - 8:12 PM
Minor Periods
12:53 AM - 2:23 PM12:19 AM - 1:49 AM
Action Rating: 2 out of 5