Climate Comfort Score
82/100
Excellent
NOAA 1991–2020 normals 58°F annual avg Public-domain federal data
Napa CO, CA Climate
Average temperature, precipitation, and a comfort score, drawn from NOAA NCEI 1991–2020 normals →
- 58°F
- Avg annual temp
- 82/100
- Comfort score
- 20.2"
- Annual precip
- 261d
- Growing season
30-year climate normals from 1 weather station (1991-2020).
The climate verdict for Napa CO
Napa CO, California averages 58°F a year and scores 82/100 on the comfort index - excellent, milder than 83% of U.S. cities.
- 58°F
- average temperature, NOAA 1991-2020 normal
- 82/100
- comfort score, milder than 83% of U.S. cities
- 20.2"
- annual precipitation
- 261 days
- growing season, frost-free days
Based on NOAA U.S. Climate Normals (1991–2020) - 30-year averages describing the typical year, not a forecast.
Avg Temperature
58°F (14°C)
Avg High
70°F
Avg Low
46°F
Annual Precip
20.2"
Comfort Score
82/100
Excellent
Avg Annual Temperature
58°F
30-year mean (NOAA NCEI)
Annual Precipitation
20.2"
Liquid-equivalent total
Comfort score vs national 100-point ceiling (Napa CO) 82.0%
National median (63)
PlainClimate composite, temperature mildness, humidity, precipitation, extreme-weather frequency. Excellent for the Napa CO area.
How Napa CO compares to every U.S. city
Napa CO's comfort score vs. all U.S. cities
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
82 Top 17% higher than 83% of 6,915 US cities
Each bar is a band; taller bars hold more US cities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Warming context for Napa CO
MethodologyHow the U.S. land temperature anomaly tracks against the global mean since 1900. The current NOAA 1991-2020 normal for Napa CO captures average conditions across the spread shown, the most recent decade is warmer than the 30-year mean.
- United States land mean (NOAA NCEI) +0.11 °C/decade
- Global anomaly (NASA GISTEMP) +0.11 °C/decade
- Paris Agreement thresholds 1.5°C / 2.0°C
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 57°F (14°C) | 38°F (3°C) | 48°F (9°C) | 4.2" | 8.7 | 0.0 |
| February | 61°F (16°C) | 40°F (4°C) | 50°F (10°C) | 4.0" | 5.4 | 0.0 |
| March | 64°F (18°C) | 42°F (5°C) | 53°F (12°C) | 3.0" | 2.2 | 0.0 |
| April | 68°F (20°C) | 44°F (6°C) | 56°F (13°C) | 1.3" | 1.4 | 0.2 |
| May | 73°F (23°C) | 48°F (9°C) | 61°F (16°C) | 0.8" | 0.0 | 1.2 |
| June | 78°F (26°C) | 52°F (11°C) | 65°F (18°C) | 0.2" | 0.0 | 3.1 |
| July | 79°F (26°C) | 55°F (13°C) | 67°F (19°C) | 0.0" | 0.0 | 2.1 |
| August | 80°F (27°C) | 54°F (12°C) | 67°F (20°C) | 0.0" | 0.0 | 2.8 |
| September | 80°F (27°C) | 51°F (11°C) | 66°F (19°C) | 0.1" | 0.0 | 5.0 |
| October | 75°F (24°C) | 46°F (8°C) | 61°F (16°C) | 0.9" | 0.1 | 1.6 |
| November | 65°F (18°C) | 40°F (5°C) | 53°F (12°C) | 2.0" | 4.9 | 0.0 |
| December | 57°F (14°C) | 38°F (3°C) | 48°F (9°C) | 3.8" | 11.2 | 0.0 |
Monthly Precipitation
Average monthly rainfall
January 4.2"
9.9 days with precipitation
February 4.0"
9.8 days with precipitation
March 3.0"
9.6 days with precipitation
April 1.3"
5.9 days with precipitation
May 0.8"
3.2 days with precipitation
June 0.2"
1.0 days with precipitation
July 0.0"
0.1 days with precipitation
August 0.0"
0.2 days with precipitation
September 0.1"
1.0 days with precipitation
October 0.9"
3.2 days with precipitation
November 2.0"
7.2 days with precipitation
December 3.8"
10.3 days with precipitation
Frost Dates & Growing Season
First Fall Freeze
November 21
50% probability date
Last Spring Freeze
March 5
50% probability date
Growing Season
261 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
2,956
Higher = more heating needed
Cooling Degree Days
315
Higher = more cooling needed
Warmest Month
August
Coldest Month
December
What Napa CO's climate means for you
Napa CO runs 58°F a year - peaking in August, coldest in December.
- Gardeners get about 261 frost-free days, with the last spring freeze near March 5 - plan the planting calendar around it, not the regional average.
- Energy bills track 2,956 heating and 315 cooling degree days a year, higher means the furnace or AC runs more.
- Comparing places to live? Line this city up against nearby cities and the national rankings. See rankings
These are 30-year NOAA normals (1991–2020) - the typical year, not a forecast for any specific season.
Climate Guides
Climate Insight: Napa CO, CA
An annual average temperature of 58°F, ranging from a mean daily high of 70°F to a mean daily low of 46°F is what the NOAA 1991–2020 climate normals report for Napa CO, California. August is typically the warmest month of the year, while December is the coldest. That baseline comes from station USW00093227 and thirty years of averaging, so it reflects a typical month rather than any one year's swings.
Anyone planning to live, garden, or travel in Napa CO should weigh precipitation alongside temperature: the annual average runs 20.2 inches, predominantly as rainfall. The frost-free season averages 261 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near March 5 and the first fall freeze near November 21. And on the energy front, 2,956 heating degree days and 315 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.
On PlainClimate's composite comfort index, Napa CO scores 82/100 (Excellent), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. Use the monthly tables above to plan around specific windows, shoulder seasons for mild highs and lows, peak summer for August-driven heat, or deep winter for December-driven cold. All figures here are thirty-year averages: any single year may run warmer, wetter, drier, or cooler than the normal, so treat them as planning guidance rather than forecasts.
Frequently Asked Questions
What is the average temperature in Napa CO, CA? ▼
The average annual temperature in Napa CO, California is 58°F. The warmest month averages 80°F (27°C) and the coldest averages 38°F (3°C).
How much rain does Napa CO get? ▼
Napa CO receives 20.2 inches of precipitation annually. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Napa CO? ▼
Napa CO has a climate comfort score of 82/100 (Excellent), milder than 83% of U.S. cities in the PlainClimate database.
When is the growing season in Napa CO? ▼
Napa CO has approximately 261 frost-free days per year, with the last spring freeze around March 5 and the first fall freeze around November 21.
How much energy does heating and cooling require in Napa CO? ▼
Napa CO has 2,956 heating degree days and 315 cooling degree days annually, a heating-dominated climate. See our <a href="/guides/reading-weather-data/" class="underline hover:text-brand-600">guide to reading weather data</a> for what these figures mean.
Where does this Napa CO climate data come from? ▼
NOAA U.S. Climate Normals v1.0.1 (1991-2020), from weather station USW00093227 near Napa CO.
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USW00093227. For informational purposes only.
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate Editorial
Every figure on PlainClimate is rendered directly from NOAA 1991-2020 U.S. Climate Normals data, no number is typed in by an editor. This page draws directly on NOAA 1991-2020 U.S. Climate Normals data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.