| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 18.8° | 6.4° | — | — | 90 |
| February | 18.7° | 6.2° | — | — | 90 |
| March | 20.4° | 7.3° | — | — | 94 |
| April | 22.1° | 8.6° | — | — | 94 |
| May | 24.4° | 10.7° | — | — | 94 |
| June | 28.5° | 13.2° | — | — | 88 |
| July | 32.4° | 16.5° | — | — | 72 |
| August | 32.9° | 17° | — | — | 70 |
| September | 31° | 15.8° | — | — | 78 |
| October | 26.6° | 12.5° | — | — | 94 |
| November | 22.4° | 8.8° | — | — | 94 |
| December | 18.4° | 6.1° | — | — | 89 |
January in Pomona averages a daily high of 18.8°C with nights around 6.4°C. Comfortable conditions for being outdoors all day.
February in Pomona averages a daily high of 18.7°C with nights around 6.2°C. Comfortable conditions for being outdoors all day.
March in Pomona averages a daily high of 20.4°C with nights around 7.3°C. Comfortable conditions for being outdoors all day.
April in Pomona averages a daily high of 22.1°C with nights around 8.6°C. Comfortable conditions for being outdoors all day.
May in Pomona averages a daily high of 24.4°C with nights around 10.7°C. Comfortable conditions for being outdoors all day.
June in Pomona averages a daily high of 28.5°C with nights around 13.2°C. Comfortable conditions for being outdoors all day.
July in Pomona averages a daily high of 32.4°C with nights around 16.5°C. Generally workable, with some weather to plan around.
August in Pomona averages a daily high of 32.9°C with nights around 17°C. Generally workable, with some weather to plan around.
September in Pomona averages a daily high of 31°C with nights around 15.8°C. Comfortable conditions for being outdoors all day.
October in Pomona averages a daily high of 26.6°C with nights around 12.5°C. Comfortable conditions for being outdoors all day.
November in Pomona averages a daily high of 22.4°C with nights around 8.8°C. Comfortable conditions for being outdoors all day.
December in Pomona averages a daily high of 18.4°C with nights around 6.1°C. Comfortable conditions for being outdoors all day.
Each month scores out of 100. It starts at 100 and loses points for daytime highs outside a 20–27°C band, for wet days, and for nights below 2°C. Nothing else is weighted in — no crowd data, no prices, no opinion. Pomona peaks at 94.
Based on 30 years of records, October–June scores highest for comfort in Pomona, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 32.9°C.
January is the wettest, averaging —mm of rain across roughly — wet days.
December is the coolest month, with average daily highs around 18.4°C.