St. Helena Weather

TownSan Francisco Bay Area

Upvalley wine town, very hot

84°
😎
Comfort Score
96(A)
Perfect
Weather updated September 9, 2026 at 9:02 PM PDT

St. Helena weather at a glance

St. Helena is a town at 262 feet in San Francisco Bay Area. Upvalley wine town, very hot. Notable features include sunny, hot, wine, and upscale.

Current conditions are 84°F, feeling like 79°F, with 24% humidity, winds near 7 mph, 55% cloud cover, and a 0% chance of precipitation. Hot with some clouds.

The location-specific climate baseline shows an average daily high of 74°F and an average low of 46°F, with about 0.0 hours of sunshine per day and 0.0 hours of morning fog per day. Expected annual precipitation is approximately 27.1 inches.

Plan your week

10-Day Forecast

  1. Today
    Sep 9
    101°67°
    Comfort
    59
    1%
    Precip 0 in
  2. Thu
    Sep 10
    101°63°
    Comfort
    58
    2%
    Precip 0 in
  3. Fri
    Sep 11
    90°54°
    Comfort
    68
    0%
    Precip 0 in
  4. Best day
    Sat
    Sep 12
    86°55°
    Comfort
    81
    0%
    Precip 0 in
  5. Sun
    Sep 13
    88°51°
    Comfort
    74
    0%
    Precip 0 in
  6. Mon
    Sep 14
    91°60°
    Comfort
    68
    0%
    Precip 0 in
  7. Tue
    Sep 15
    90°55°
    Comfort
    67
    0%
    Precip 0 in
  8. Wed
    Sep 16
    92°54°
    Comfort
    64
    1%
    Precip 0 in
  9. Thu
    Sep 17
    96°58°
    Comfort
    59
    1%
    Precip 0 in
  10. Fri
    Sep 18
    97°62°
    Comfort
    58
    2%
    Precip 0 in

Pick your time

Hourly Forecast

  1. Today
    Now
    84°
    Comfort
    96
    1%
    0 in
  2. Today
    10 PM
    82°
    Comfort
    99
    1%
    0 in
  3. Today
    11 PM
    81°
    Comfort
    97
    1%
    0 in
  4. Thu
    12 AM
    79°
    Comfort
    99
    1%
    0 in
  5. Thu
    1 AM
    78°
    Comfort
    94
    1%
    0 in
  6. Thu
    2 AM
    78°
    Comfort
    97
    1%
    0 in
  7. Thu
    3 AM
    77°
    Comfort
    93
    2%
    0 in
  8. Thu
    4 AM
    76°
    Comfort
    94
    1%
    0 in
  9. Thu
    5 AM
    74°
    Comfort
    97
    1%
    0 in
  10. Thu
    6 AM
    71°
    Comfort
    99
    1%
    0 in
  11. Sunrise6:47 AM
  12. Thu
    7 AM
    69°
    Comfort
    98
    1%
    0 in
  13. Thu
    8 AM
    71°
    Comfort
    100
    1%
    0 in
  14. Thu
    9 AM
    76°
    Comfort
    96
    1%
    0 in
  15. Thu
    10 AM
    84°
    Comfort
    88
    1%
    0 in
  16. Thu
    11 AM
    91°
    Comfort
    70
    1%
    0 in
  17. Thu
    12 PM
    96°
    Comfort
    60
    1%
    0 in
  18. Thu
    1 PM
    101°
    Comfort
    56
    1%
    0 in
  19. Thu
    2 PM
    100°
    Comfort
    61
    1%
    0 in
  20. Thu
    3 PM
    99°
    Comfort
    63
    1%
    0 in
  21. Thu
    4 PM
    97°
    Comfort
    73
    1%
    0 in
  22. Thu
    5 PM
    95°
    Comfort
    80
    1%
    0 in
  23. Thu
    6 PM
    91°
    Comfort
    86
    0%
    0 in
  24. Thu
    7 PM
    87°
    Comfort
    95
    0%
    0 in
  25. Sunset7:25 PM
  26. Thu
    8 PM
    78°
    Comfort
    100
    0%
    0 in
  27. Thu
    9 PM
    72°
    Comfort
    100
    0%
    0 in
  28. Thu
    10 PM
    67°
    Comfort
    98
    0%
    0 in
  29. Thu
    11 PM
    63°
    Comfort
    95
    0%
    0 in
  30. Fri
    12 AM
    61°
    Comfort
    92
    0%
    0 in
  31. Fri
    1 AM
    58°
    Comfort
    90
    0%
    0 in
  32. Fri
    2 AM
    57°
    Comfort
    88
    0%
    0 in
  33. Fri
    3 AM
    56°
    Comfort
    88
    0%
    0 in
  34. Fri
    4 AM
    55°
    Comfort
    87
    0%
    0 in
  35. Fri
    5 AM
    55°
    Comfort
    86
    0%
    0 in
  36. Fri
    6 AM
    54°
    Comfort
    86
    0%
    0 in
  37. Sunrise6:48 AM
  38. Fri
    7 AM
    54°
    Comfort
    86
    0%
    0 in
  39. Fri
    8 AM
    54°
    Comfort
    86
    0%
    0 in
  40. Fri
    9 AM
    57°
    Comfort
    87
    0%
    0 in
  41. Fri
    10 AM
    65°
    Comfort
    97
    0%
    0 in
  42. Fri
    11 AM
    73°
    Comfort
    100
    0%
    0 in
  43. Fri
    12 PM
    81°
    Comfort
    92
    0%
    0 in
  44. Fri
    1 PM
    88°
    Comfort
    72
    0%
    0 in
  45. Fri
    2 PM
    89°
    Comfort
    72
    0%
    0 in
  46. Fri
    3 PM
    90°
    Comfort
    80
    0%
    0 in
  47. Fri
    4 PM
    90°
    Comfort
    83
    0%
    0 in
  48. Fri
    5 PM
    89°
    Comfort
    87
    0%
    0 in
  49. Fri
    6 PM
    86°
    Comfort
    91
    0%
    0 in
  50. Fri
    7 PM
    78°
    Comfort
    99
    0%
    0 in
  51. Sunset7:23 PM
  52. Fri
    8 PM
    70°
    Comfort
    99
    0%
    0 in

Current Conditions

Temperature
84°F
Feels like 79°F
Humidity
24%
Dew point 43°F
Wind
7 mph
NW • Gusts 9 mph
Cloud Cover
55%
High clouds
Precip Chance
0%

Comfort Breakdown

Less comfortableMore comfortable
Thermal94
Wind100
Night Sky94
Moisture100
Precipitation100

Weather Maps

About the weather maps for St. Helena

Each preview is centered on St. Helena, with the red pin marking its approximate location. Satellite imagery provides cloud context, radar shows nearby precipitation, and the fog view shows the marine-layer or low-cloud field when that regional layer is available.

These images cover a wider area than the point forecast, so a nearby cloud or rain band may not be directly over St. Helena. Open a preview for the interactive map and its latest timestamp before making a weather-sensitive decision.

Climate Dashboard

Current conditions vs. NOAA normals and recent destination baseline

Today's High vs Normal
101°Fforecast
14° above normal
Normal: 87°F
Rainfall Year-to-Date
17.0"
15% below average
30-yr avg: 20.0"
Sunny Days
24last 28 days
1 fewer than baseline
Recent baseline: 25
Foggy Days
6last 28 days
About average
Avg Wind Speed
5.4 mphlast 28 days
1.3 mph calmer than baseline
Recent baseline: 6.8 mph
Comfort Score
8628-day avg
3 pts below typical
Recent baseline: 89
What the St. Helena climate comparisons mean

These cards compare recent conditions at St. Helena with the available local baseline. Temperature and year-to-date rainfall use long-term normals when available; fog, sunshine, wind, and comfort use the matching recent or modeled baseline identified on each card.

Positive and negative differences describe how St. Helena departs from its own usual pattern. They should not be read as a direct comparison with another city or as a forecast beyond the period shown.

Historical Climate Data

Long-term weather patterns and climate data

Data sources: NOAA URMA for recent temperature history, NOAA Stage IV for recent precipitation, NOAA HRRR for fog, cloud, wind, humidity, and sunshine signals, and NOAA 1991-2020 climate normals for long-term baselines.

Climate Overview

Based on NOAA 30-year temperature/rain normals (1991-2020) with recent fog/sun baseline

83
Avg Comfort
74°
Avg High
45.7°
Avg Low
74%
Perfect Days
☀️ Avg Sunshine (recent)9.4h/day
🌫️ Avg Fog (recent)1.4h/day
💧 Avg Annual Rain27.1"
🌧️ Rainy Days/yr93 (25%)
🌫️ Foggy Days/yr (recent)72
✨ Perfect Days (80+)475

🌟 Best Months to Visit

1. June81
85.4° / 52.3° · ☀️ 13.6h
0 foggy days · 5 rainy days
2. May79
77.8° / 48.1° · ☀️ 12.4h
3 foggy days · 6 rainy days
3. July74
89.1° / 54.1° · ☀️ 13.1h
0 foggy days · 5 rainy days

⚠️ Challenging Months

1. December31
57.4° / 37.4° · ☀️ 5.8h
💧 6.2" · 12 rainy days · 14 foggy days
2. February41
62° / 39.8° · ☀️ 6.1h
💧 5.6" · 12 rainy days · 9 foggy days
3. January42
57.9° / 37.8° · ☀️ 7.6h
💧 6.2" · 12 rainy days · 7 foggy days

Monthly Breakdown

MonthComfortHigh/Low☀️ Sun🌫️ Fog💧 RainPerfect
August 20248491.5° / 60.1°12.2h1d0.1"20
September 20248690.1° / 58.9°11.1h1d0.25"23
October 20248583.8° / 57.6°9.5h3d0.46"22
November 20247762.3° / 44.6°7h8d8.86"18
December 20247261.1° / 44.6°5.8h13d9.23"17
January 20258461° / 42.1°8h5d1.33"25
February 20257260.3° / 42.7°5.9h10d11.24"17
March 20257661.5° / 43.5°8.5h7d5.23"18
April 20258970.3° / 47.5°10.6h7d0.58"24
May 20259080.3° / 53°13h2d0.22"29
June 20259185.1° / 55.5°13.6h0d0"28
July 20259385.3° / 57.4°13.1h0d0.12"31
August 20258791.6° / 60.8°12.5h0d0.01"26
September 20258785.5° / 59.8°10.4h3d0.5"25
October 20258573.3° / 53°8.1h8d2.57"21
November 20257966.9° / 49.9°7.1h16d4.98"20
December 20257261.4° / 46.2°5.9h15d9.95"17
January 20268162.4° / 43.2°7.2h8d4.68"21
February 20267463.2° / 45.2°6.3h8d5.6"16
March 20269277.5° / 52.2°10.7h2d1.21"28
April 20268267.7° / 48.2°10.2h9d5.14"21
May 20268874.1° / 51.9°10.6h2d0.41"8
Last updated: 5/10/2026

Climate Trends

Average Temperature by Month

96°F81°F66°F50°F35°FOct '24Nov '24Dec '24Jan '25Feb '25Mar '25Apr '25May '25Jun '25Jul '25Aug '25Sep '25Oct '25Nov '25Dec '25Jan '26Feb '26Mar '26Apr '26May '26Jun '26Jul '26Aug '26
Average High
Average Low
About the St. Helena climate charts

The temperature chart compares average monthly highs and lows at St. Helena, showing both the seasonal cycle and the typical day-to-night range. The comfort chart summarizes how often the combined weather pattern is favorable rather than judging temperature alone.

Precipitation shows the total recorded or modeled rainfall for each month at St. Helena. Sunshine compares average bright-sky hours with the daylight available, while fog shows the average number of morning fog or low-cloud hours per day. Switch between the chart tabs to compare the same months across each measure.

Hourly Temperature, Fog, Wind, Cloud Cover, and Solar Radiation Patterns

Average local hour by month from 2014-09-30 to 2026-04-30

How to read the temperature heatmap for St. Helena

This heatmap shows how average temperature at St. Helena changes by hour and month. Read left to right for the seasons and top to bottom for the time of day; warmer colors identify the usual afternoon peaks and cooler colors show overnight and winter lows.

Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.

How to read the fog heatmap for St. Helena

This heatmap shows when fog or low cloud is most likely at St. Helena. Darker cells mark month-and-hour combinations with a stronger historical fog signal, which helps separate overnight or morning fog from cloud that tends to linger into the afternoon.

Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.

How to read the wind heatmap for St. Helena

This heatmap shows the typical hourly wind pattern at St. Helena through the year. It makes recurring afternoon wind, calmer overnight periods, and seasonal changes easier to compare than a single daily wind value.

Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.

How to read the cloud cover heatmap for St. Helena

This heatmap shows average cloud cover at St. Helena for every month and hour. Use it to see whether cloudiness is mainly an overnight and morning pattern or commonly persists during the part of the day you plan to visit.

Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.

How to read the solar radiation heatmap for St. Helena

This heatmap shows the average solar radiation reaching St. Helena by month and hour. Brighter cells indicate the strongest typical sun, while muted cells can reflect nighttime, shorter winter days, cloud cover, smoke, or terrain shading.

Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage; the red marker shows the current month and hour.

Loading interactive climate heatmaps…

Location Details

📍
Coordinates
38.5052, -122.4697
⛰️
Elevation
262 ft
🏷️
Type
Town
🏷️
Tags
#sunny#hot#wine#upscale
Map
Loading map...
Get Directions →

Frequently Asked Questions

Everything you need to know about weather and visiting St. Helena

What is the weather at St. Helena right now?

Current conditions at St. Helena are 84°F, feeling like 79°F, with 24% humidity, winds near 7 mph, 55% cloud cover, and a 0% chance of precipitation. Hot with some clouds

What temperatures are typical at St. Helena?

The location-specific record for 1991-01-01 through 2020-12-31 shows an average daily high of 74°F and an average low of 46°F at St. Helena. These are averages across the year; the monthly climate table on this page shows the warmer and cooler seasons separately.

How much rain does St. Helena get?

The location-specific climate baseline estimates about 27.1 inches of precipitation and 93 days with measurable rain in a typical year at St. Helena. The monthly breakdown shows when that rain is most likely.

How often is St. Helena foggy?

St. Helena averages about 0.0 hours of morning fog per day across the location-specific climate baseline, with approximately 0 foggy days in a typical year. Fog varies considerably by season, so check the monthly breakdown and current forecast for visit planning.

What are the best months to visit St. Helena for comfortable weather?

Based on the destination's recorded comfort, temperature, sunshine, rain, and fog data, the strongest months are July 2025 (85°F/57°F average high/low and a 93 comfort score), March 2026 (78°F/52°F average high/low and a 92 comfort score), and June 2025 (85°F/56°F average high/low and a 91 comfort score). “Best” depends on the activity, so use the monthly table for the exact tradeoffs.

What kind of destination is St. Helena?

St. Helena is a town at 262 feet. Upvalley wine town, very hot. Notable features include sunny, hot, wine, and upscale.

💡 Local Tip: San Francisco Bay Area weather can change dramatically within short distances and throughout the day. Always check current conditions before visiting St. Helena.