January is one of the cooler months of the year in Pasadena, with average highs near 17.8°C and lows around 7.4°C (mean 12.6°C). It is a relatively wet time of year, averaging 77 mm of rainfall and 61% relative humidity across the period.
January is one of the cooler months of the year in Pasadena. Across 45 years of records, the warmest January in Pasadena was 2003 — when the month averaged 16.6°C — while the coldest were 1982 and 1985 at 10.3°C. Typical January days reach 17.8°C with nights near 7.4°C. The long-term trend is warming, about 0.4°C per decade.
January is a relatively wet time of year in Pasadena, averaging 77 mm of rainfall. The wettest January on record was 1995 with 355 mm, while the driest was 2003 at 0 mm.
Relative humidity in Pasadena during January averages 61%. The most humid January was 1995 at 82%, and the least humid was 2014 at 43%.
January receives about 3.1 kWh/m²/day of solar energy in Pasadena. The sunniest January was 2025 at 3.5 kWh/m²/day, and the cloudiest was 1995 at 2.4.
Average wind speed in Pasadena during January is 2.5 m/s. The windiest Januarys were 1982 and 1989 at 3.2 m/s, while the calmest was 2015 at 1.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 11.9°C | 12.2°C | 12.7°C | 13.5°C | 12.8°C | +0.9°C |
| Avg High | 17.4°C | 17.2°C | 17.8°C | 18.7°C | 17.9°C | +0.5°C |
| Avg Low | 6.4°C | 7.2°C | 7.6°C | 8.3°C | 7.7°C | +1.3°C |
| Avg Rain | 56 mm | 116 mm | 66 mm | 82 mm | 56 mm | +0 mm |
January temperatures in Pasadena have risen by about 0.8°C between 1981–1985 and 2021–2025.
January has ranged from a record low of -1°C (2002) to a record high of 30.4°C (2003).
Rainfall in January is a relatively wet time of year, averaging 77 mm, with a wettest year of 355 mm.
A quieter season to visit Pasadena
If your dates are flexible, the more temperate months of June and September tend to be the most comfortable for visiting Pasadena. That said, January — with days averaging 17.8°C and nights around 7.4°C (mean 12.6°C) and moderate rainfall (77 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 18.7°C | 13.2°C | 7.7°C | 25.2°C | 3.7°C | 19 mm | 50% | 2.3 m/s | 3.5 |
| 2024 | 17.7°C | 12.8°C | 8.0°C | 24.1°C | 2.2°C | 44 mm | 69% | 2.1 m/s | 3.1 |
| 2023 | 14.6°C | 10.6°C | 6.7°C | 19.1°C | 2.4°C | 211 mm | 76% | 2.6 m/s | 2.8 |
| 2022 | 18.6°C | 13.3°C | 8.1°C | 22.1°C | 2.7°C | 3 mm | 63% | 2 m/s | 3.3 |
| 2021 | 19.0°C | 13.6°C | 8.1°C | 29.9°C | 1.5°C | 52 mm | 55% | 2.5 m/s | 3.2 |
| 2020 | 18.5°C | 13.1°C | 7.7°C | 24.4°C | 3.9°C | 8 mm | 68% | 2 m/s | 3.4 |
| 2019 | 17.1°C | 12.7°C | 8.3°C | 23.1°C | 2.5°C | 182 mm | 72% | 2.2 m/s | 2.9 |
| 2018 | 21.4°C | 15.9°C | 10.4°C | 27.7°C | 3.4°C | 72 mm | 52% | 2 m/s | 3.2 |
| 2017 | 15.0°C | 11.1°C | 7.2°C | 22.3°C | 2.1°C | 222 mm | 76% | 2.3 m/s | 2.9 |
| 2016 | 17.0°C | 12.3°C | 7.6°C | 22.1°C | 4.1°C | 94 mm | 69% | 2.1 m/s | 2.8 |
| 2015 | 20.2°C | 14.9°C | 9.5°C | 25.5°C | 1.5°C | 31 mm | 57% | 1.7 m/s | 3.2 |
| 2014 | 22.5°C | 16.5°C | 10.5°C | 27.1°C | 6.4°C | 2 mm | 43% | 2 m/s | 3.3 |
| 2013 | 17.3°C | 11.5°C | 5.7°C | 24.0°C | 0.0°C | 31 mm | 52% | 2.3 m/s | 3.3 |
| 2012 | 20.6°C | 14.5°C | 8.4°C | 27.7°C | 1.9°C | 23 mm | 47% | 2.2 m/s | 3.4 |
| 2011 | 17.8°C | 12.4°C | 7.0°C | 26.3°C | 1.4°C | 19 mm | 63% | 2.3 m/s | 3.3 |
| 2010 | 17.8°C | 12.9°C | 8.0°C | 24.2°C | 3.3°C | 147 mm | 64% | 2.4 m/s | 2.8 |
| 2009 | 20.2°C | 14.4°C | 8.6°C | 26.7°C | 1.7°C | 10 mm | 51% | 2.5 m/s | 3.4 |
| 2008 | 15.2°C | 10.8°C | 6.4°C | 21.9°C | 1.8°C | 196 mm | 68% | 3 m/s | 2.9 |
| 2007 | 16.5°C | 11.2°C | 5.8°C | 24.8°C | -0.2°C | 17 mm | 51% | 2.6 m/s | 3.4 |
| 2006 | 18.3°C | 12.7°C | 7.2°C | 26.5°C | 2.4°C | 38 mm | 58% | 2.8 m/s | 3.4 |
| 2005 | 16.1°C | 12.1°C | 8.1°C | 23.9°C | 3.3°C | 245 mm | 77% | 2.6 m/s | 2.8 |
| 2004 | 17.9°C | 12.7°C | 7.5°C | 24.0°C | 2.3°C | 12 mm | 57% | 2.1 m/s | 3.3 |
| 2003 🔥 | 22.4°C | 16.6°C | 10.8°C | 30.4°C | 4.5°C | 0 mm | 53% | 2.3 m/s | 3.3 |
| 2002 | 17.4°C | 11.9°C | 6.4°C | 25.0°C | -1.0°C | 15 mm | 54% | 2.2 m/s | 3.3 |
| 2001 | 15.9°C | 11.1°C | 6.2°C | 25.0°C | 1.9°C | 95 mm | 61% | 2.2 m/s | 3.1 |
| 2000 | 18.5°C | 13.5°C | 8.5°C | 24.8°C | 3.9°C | 28 mm | 63% | 2.1 m/s | 2.8 |
| 1999 | 18.6°C | 13.3°C | 8.0°C | 24.5°C | 2.9°C | 40 mm | 57% | 2.2 m/s | 3.2 |
| 1998 | 17.1°C | 12.4°C | 7.8°C | 22.5°C | 2.6°C | 71 mm | 72% | 2 m/s | 2.9 |
| 1997 | 15.7°C | 11.6°C | 7.5°C | 21.4°C | 2.1°C | 137 mm | 76% | 2.6 m/s | 2.7 |
| 1996 | 18.4°C | 13.1°C | 7.7°C | 25.2°C | 1.4°C | 64 mm | 61% | 2.5 m/s | 2.9 |
| 1995 🌧️ | 14.4°C | 10.9°C | 7.3°C | 22.9°C | 2.4°C | 355 mm | 82% | 2.7 m/s | 2.4 |
| 1994 | 19.5°C | 13.7°C | 7.8°C | 26.0°C | 2.7°C | 15 mm | 47% | 2.4 m/s | 3.4 |
| 1993 | 14.5°C | 10.5°C | 6.6°C | 19.6°C | 0.3°C | 319 mm | 77% | 3 m/s | 2.6 |
| 1992 | 17.8°C | 12.1°C | 6.3°C | 23.3°C | 3.1°C | 61 mm | 55% | 3 m/s | 3.1 |
| 1991 | 17.7°C | 12.0°C | 6.4°C | 24.5°C | 3.4°C | 42 mm | 57% | 2.4 m/s | 3.2 |
| 1990 | 17.8°C | 12.2°C | 6.6°C | 24.9°C | 2.4°C | 58 mm | 56% | 2.8 m/s | 3.2 |
| 1989 | 16.3°C | 10.4°C | 4.5°C | 23.7°C | -0.4°C | 16 mm | 55% | 3.2 m/s | 3.3 |
| 1988 | 16.7°C | 11.2°C | 5.7°C | 22.3°C | 0.5°C | 57 mm | 61% | 2.9 m/s | 2.9 |
| 1987 | 16.6°C | 10.9°C | 5.2°C | 24.7°C | -0.6°C | 50 mm | 55% | 3 m/s | 3 |
| 1986 | 20.4°C | 14.9°C | 9.4°C | 26.4°C | 6.5°C | 72 mm | 60% | 2.4 m/s | 3 |
| 1985 | 15.7°C | 10.3°C | 5.0°C | 20.0°C | -0.3°C | 22 mm | 64% | 2.7 m/s | 3.2 |
| 1984 | 18.6°C | 12.9°C | 7.2°C | 23.6°C | 3.1°C | 3 mm | 55% | 3.1 m/s | 3.4 |
| 1983 | 17.9°C | 12.6°C | 7.3°C | 24.4°C | 1.4°C | 137 mm | 62% | 2.9 m/s | — |
| 1982 ❄️ | 15.8°C | 10.3°C | 4.8°C | 22.9°C | -0.6°C | 82 mm | 60% | 3.2 m/s | — |
| 1981 | 18.5°C | 13.4°C | 8.4°C | 23.1°C | 0.9°C | 64 mm | 57% | 2.5 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 17.8°C with lows near 7.4°C (mean 12.6°C), based on 45 years of NASA POWER data.
January averages 77 mm of rainfall in Pasadena, a relatively wet time of year. The wettest on record was 355 mm in 1995.
The hottest January reached 30.4°C in 2003. The coldest dipped to -1°C in 2002.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 0.8°C. Daytime highs moved from 17.3°C to 17.7°C and overnight lows from 6.5°C to 7.7°C over the same span.
January is one of the cooler months of the year in Pasadena and a relatively wet time of year, so plan for around 17.8°C daytime highs and 7.4°C at night.
Yes — January is the coldest month of the year in Pasadena, averaging 12.6°C.
For January in Pasadena, pack warm layers and a jacket for chilly mornings, with typical highs of 17.8°C and lows of 7.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 61% — moderately humid.
Average wind speed in January is 2.5 m/s. The windiest January on record averaged 3.2 m/s (1982).
The wettest January on record was 1995 with 355 mm. On average, January sees 77 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Pasadena behaves each January, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for January specifically, along with year-by-year records and how the month has changed over the decades.
