High temperaturesForecast day 1
1.2°Ftypical miss
0°3°F8°+
95% came within 3°F
Usually coolerUsually warmerLittle warm or cool tendency
Local temperature forecast performance
How accurate are temperature forecasts in Phoenix, Arizona?
Nighttime lows were less predictable than daytime highs in Phoenix's next-day record. Lows missed by 1.8°F on average, compared with 1.2°F for highs.
See the current Phoenix forecast
Opens ZIP 85004 using the nearest current station, which may differ from the archive station below.
What stands out
Phoenix forecast findings
- Error increased more quickly for daily high forecasts. From forecast day 1 to day 7, their typical miss grew by 1.8°F; day-7 errors reached 3.0°F for highs and 3.0°F for lows.
- On forecast day 1, May highs had the smallest typical miss (0.9°F), while July lows had the largest (2.3°F).
- Across days 1, 3, 5, and 7, Phoenix's typical error was 1.3°F lower than the national archive average.
- The strongest monthly directional tendency appeared in May lows, when forecasts averaged 1.5°F cooler than observed.
At a glance
Forecast day 1 accuracy
Highs Lows
Lower error than the national average
Phoenix: 2.2°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
1.8°Ftypical miss
0°3°F8°+
88% 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: 95%Low: 88%
Day 3High: 87%Low: 79%
Day 5High: 77%Low: 70%
Day 7High: 65%Low: 63%
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
Jan1.3°61 cases
Feb1.1°55 cases
Mar1.2°59 cases
Apr1.1°60 cases
May0.9°57 cases
Jun1.1°60 cases
Jul1.5°60 cases
Aug1.3°59 cases
Sep1.5°59 cases
Oct1.5°62 cases
Nov1.2°53 cases
Dec1.1°57 cases
Low temperatures
Jan2.1°61 cases
Feb1.2°55 cases
Mar1.8°59 cases
Apr1.6°60 cases
May1.7°59 cases
Jun1.8°60 cases
Jul2.3°59 cases
Aug2.1°60 cases
Sep1.5°59 cases
Oct1.9°62 cases
Nov1.4°53 cases
Dec1.8°57 cases
Data locationPHOENIX/SKY HARBOR (PHX)3.6 miles from central Phoenix · Archive 2024-08-01–2026-07-28
Based on archived raw NBM forecasts compared with observed daily highs and lows near Phoenix. 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.