Climate Comfort Score
82/100
Excellent
2026 data Public-data reference. official source
MT Diablo Junction, CA Climate
Temperature, precipitation, and comfort score from NOAA NCEI 1991-2020 normals →
30-year climate normals from 1 weather station (1991-2020).
MT Diablo Junction, California has an average annual temperature of 58°F and a climate comfort score of 82/100 (Excellent). Annual precipitation totals 26.1", including 0.7" of snow. Based on NOAA 30-year normals (1991–2020).
Avg Temperature
58°F (15°C)
Avg High
67°F
Avg Low
50°F
Annual Precip
26.1"
Annual Snow
0.7"
Comfort Score
82/100
Excellent
Avg Annual Temperature
58°F
30-year mean (NOAA NCEI)
Annual Precipitation
26.1"
Plus 0.7" of snow
Comfort score vs national 100-point ceiling (MT Diablo Junction) 82.0%
National median (≈55)
PlainClimate composite — temperature mildness, humidity, precipitation, extreme-weather frequency. Excellent for the MT Diablo Junction area.
Warming context for MT Diablo Junction
MethodologyHow the U.S. land temperature anomaly tracks against the global mean since 1900. The current NOAA 1991-2020 normal for MT Diablo Junction 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 | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 54°F (12°C) | 42°F (5°C) | 48°F (9°C) | 5.1" | 0.1" | 4.3 | 0.0 |
| February | 55°F (13°C) | 42°F (5°C) | 48°F (9°C) | 4.9" | 0.5" | 3.8 | 0.0 |
| March | 58°F (14°C) | 43°F (6°C) | 50°F (10°C) | 3.7" | 0.1" | 2.5 | 0.0 |
| April | 62°F (17°C) | 44°F (7°C) | 53°F (12°C) | 1.9" | 0.0" | 1.8 | 0.0 |
| May | 68°F (20°C) | 49°F (10°C) | 59°F (15°C) | 1.1" | 0.0" | 0.0 | 0.8 |
| June | 76°F (24°C) | 55°F (13°C) | 66°F (19°C) | 0.3" | 0.0" | 0.0 | 3.7 |
| July | 83°F (28°C) | 62°F (16°C) | 72°F (22°C) | 0.0" | 0.0" | 0.0 | 7.5 |
| August | 83°F (28°C) | 61°F (16°C) | 72°F (22°C) | 0.0" | 0.0" | 0.0 | 7.9 |
| September | 80°F (27°C) | 60°F (15°C) | 70°F (21°C) | 0.1" | 0.0" | 0.0 | 5.8 |
| October | 72°F (22°C) | 54°F (12°C) | 63°F (17°C) | 1.2" | 0.0" | 0.0 | 1.3 |
| November | 60°F (16°C) | 46°F (8°C) | 53°F (12°C) | 2.6" | 0.0" | 1.9 | 0.0 |
| December | 53°F (12°C) | 41°F (5°C) | 47°F (9°C) | 5.1" | 0.0" | 4.5 | 0.0 |
Monthly Precipitation
Average monthly rainfall and snowfall
January 5.1"
Snow: 0.1"
11.8 days with precipitation
February 4.9"
Snow: 0.5"
11.1 days with precipitation
March 3.7"
Snow: 0.1"
10.2 days with precipitation
April 1.9"
6.7 days with precipitation
May 1.1"
4.4 days with precipitation
June 0.3"
1.3 days with precipitation
July 0.0"
0.3 days with precipitation
August 0.0"
0.4 days with precipitation
September 0.1"
0.9 days with precipitation
October 1.2"
3.4 days with precipitation
November 2.6"
7.4 days with precipitation
December 5.1"
10.5 days with precipitation
Frost Dates & Growing Season
First Fall Freeze
December 22
50% probability date
Last Spring Freeze
March 8
50% probability date
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
3,309
Higher = more heating needed
Cooling Degree Days
925
Higher = more cooling needed
Warmest Month
July
Coldest Month
December
Related Data
PlainEnviro
EPA environmental data — pollution, water quality, and environmental health by location
PlainCarbon
Carbon emissions data — greenhouse gas reporting and facility-level CO2 data
PlainHazard
Natural disaster data — weather-related hazards, FEMA declarations, and risk profiles
PlainAirData
EPA air quality data — AQI readings, pollutant levels, and air quality trends
Climate Guides
Climate Insight: MT Diablo Junction, CA
The NOAA 1991–2020 climate normals describe MT Diablo Junction, California as a location with an annual average temperature of 58°F, ranging from a mean daily high of 67°F to a mean daily low of 50°F. July is typically the warmest month of the year, while December is the coldest. These thirty-year averages, computed from station USC00045915, smooth out year-to-year variability and give a baseline expectation for typical conditions in any given month.
Precipitation patterns matter as much as temperature for anyone planning to live, garden, or travel here. MT Diablo Junction receives roughly 26.1 inches of precipitation each year, with 0.7 inches typically falling as snow. Growing-season length varies with elevation and microclimate, with the last spring freeze near March 8 and the first fall freeze near December 22. For energy use, 3,309 heating degree days and 925 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.
On PlainClimate's composite comfort index, MT Diablo Junction 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 July-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 MT Diablo Junction, CA? ▼
The average annual temperature in MT Diablo Junction, California is 58°F. The warmest month averages 83°F (28°C) and the coldest averages 41°F (5°C).
How much rain does MT Diablo Junction get? ▼
MT Diablo Junction receives 26.1 inches of precipitation annually, including 0.7 inches of snow. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for MT Diablo Junction? ▼
MT Diablo Junction has a climate comfort score of 82/100 (Excellent). This score considers temperature mildness, humidity, precipitation, and extreme weather frequency.
When is the growing season in MT Diablo Junction? ▼
Growing season data is not available for MT Diablo Junction.
How much energy does heating and cooling require in MT Diablo Junction? ▼
MT Diablo Junction has 3,309 heating degree days and 925 cooling degree days annually. Higher heating degree days indicate greater winter energy demand, while higher cooling degree days indicate greater summer cooling needs.
Where does this MT Diablo Junction climate data come from? ▼
All climate data comes from NOAA U.S. Climate Normals v1.0.1, covering the 30-year period from 1991 to 2020. Data is collected from weather station USC00045915. These 30-year averages are the standard reference for typical weather conditions.
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USC00045915. 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
