High temperaturesForecast day 1
2.5°Ftypical miss
0°3°F8°+
70% came within 3°F
Usually coolerUsually warmerLittle warm or cool tendency
Local temperature forecast performance
How accurate are temperature forecasts in San Jose, California?
Daytime highs were the harder part of the next-day temperature forecast in San Jose. Highs missed by 2.5°F on average, compared with 2.2°F for nighttime lows.
See the current San Jose forecast
Opens ZIP 95113 using the nearest current station, which may differ from the archive station below.
What stands out
San Jose forecast findings
- Error increased more quickly for daily high forecasts. From forecast day 1 to day 7, their typical miss grew by 1.4°F; day-7 errors reached 3.9°F for highs and 3.0°F for lows.
- On forecast day 1, August lows had the smallest typical miss (1.3°F), while December highs had the largest (4.5°F).
- Across days 1, 3, 5, and 7, San Jose's typical error was 0.7°F lower than the national archive average.
- The strongest monthly directional tendency appeared in October highs, when forecasts averaged 1.8°F cooler than observed.
At a glance
Forecast day 1 accuracy
Highs Lows
Lower error than the national average
San Jose: 2.9°F typical miss National archive average: 3.5°F
Combined high and low results across forecast days 1, 3, 5, and 7.Low temperaturesForecast day 1
2.2°Ftypical miss
0°3°F8°+
76% came within 3°F
Usually coolerUsually warmerLittle warm or cool tendency
Error generally grows farther into the forecast
The dots show the typical miss on each forecast day.
See within-3°F percentages and window timing
Day 1High: 70%Low: 76%
Day 3High: 66%Low: 69%
Day 5High: 57%Low: 68%
Day 7High: 52%Low: 62%
High and low windows represent the same numbered forecast day, but the high window ends 12 hours later and therefore has 12 more hours of lead time.
How forecasts change through the year
Each tile is forecast day 1’s typical miss.
Under 2°F2–3°F3–5°FOver 5°FNot enough data
Forecasts ran coolerLittle tendencyForecasts ran warmer
High temperatures
Jan2.7°60 cases
Feb2.2°55 cases
Mar1.5°60 cases
Apr1.8°57 cases
May2.0°58 cases
Jun3.2°58 cases
Jul1.9°60 cases
Aug3.2°59 cases
Sep2.6°60 cases
Oct2.5°62 cases
Nov2.1°54 cases
Dec4.5°57 cases
Low temperatures
Jan3.3°60 cases
Feb2.7°55 cases
Mar2.4°60 cases
Apr2.0°59 cases
May1.9°58 cases
Jun1.3°58 cases
Jul1.7°59 cases
Aug1.3°60 cases
Sep1.8°60 cases
Oct2.7°62 cases
Nov3.1°54 cases
Dec3.0°57 cases
Data locationSAN JOSE INTL A (SJC)2.6 miles from central San Jose · Archive 2024-08-01–2026-07-28
Based on archived raw NBM forecasts compared with observed daily highs and lows near San Jose. Results describe this model archive, not every forecast provider.
How these numbers are calculated
The forecasts are raw NBM median temperature guidance initialized at 12Z. Results include multiple NBM model eras and are retrospective, so they describe this archive rather than guaranteeing future performance.
“Typical miss” is mean absolute error: the average size of the error regardless of direction. Warmer or cooler tendency is signed bias, which can be small even when individual errors are larger.