Half Moon Bay weather in January: Half Moon Bay, California: normal highs, lows, rain and records for January
Half Moon Bay in January has a normal high of 59°F and a normal low of 43°F, a daily mean of 51°F, holding near 59°F all month. Measurable precipitation falls on 14 days in a normal January, 5.07 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 15°C and low of 6°C, 129 mm of precipitation in January.
- NOAA stationHalf Moon Bay
- Station IDUSC00043714
- Location37.47°N 122.44°W
- Elevation27 ft (8 m)
- Population11,324
- Jan 59° 43°
- Feb 60° 43°
- Mar 60° 44°
- Apr 61° 45°
- May 62° 48°
- Jun 64° 50°
- Jul 65° 53°
- Aug 66° 54°
- Sep 66° 51°
- Oct 66° 48°
- Nov 63° 45°
- Dec 59° 43°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Half Moon Bay in January?
The normal high is 59°F and the normal low 43°F, for a daily mean of 51.4°F. January is 0.5°F warmer than December and 0.1°F warmer than February. January is the 10th warmest month of the year in Half Moon Bay and the 2nd wettest. Across the month the normal high rises 1°F, from 59°F on January 1 to 60°F on January 31. From one year to the next January's mean temperature typically moves about 1.7°F either way (NOAA's standard deviation), so roughly two Januarys in three average between 50°F and 53°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 46%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| January 1 | 59°F | 43°F | 45% | 27% |
| January 8 | 59°F | 43°F | 46% | 27% |
| January 15 | 60°F | 44°F | 46% | 27% |
| January 22 | 60°F | 44°F | 46% | 28% |
| January 31 | 60°F | 43°F | 46% | 28% |
Every day of January: normal high, low and chance of precipitation (warmest afternoon January 20, coldest night January 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| January 1 | 59°F | 43°F | 45% | 27% | 9 h 40 min |
| January 2 | 59°F | 43°F | 45% | 27% | 9 h 40 min |
| January 3 | 59°F | 43°F | 45% | 27% | 9 h 40 min |
| January 4 | 59°F | 43°F | 45% | 27% | 9 h 40 min |
| January 5 | 59°F | 43°F | 45% | 27% | 9 h 40 min |
| January 6 | 59°F | 43°F | 45% | 27% | 9 h 40 min |
| January 7 | 59°F | 43°F | 46% | 27% | 9 h 40 min |
| January 8 | 59°F | 43°F | 46% | 27% | 9 h 40 min |
| January 9 | 59°F | 43°F | 46% | 27% | 9 h 40 min |
| January 10 | 59°F | 44°F | 46% | 26% | 9 h 40 min |
| January 11 | 59°F | 44°F | 46% | 27% | 9 h 50 min |
| January 12 | 59°F | 44°F | 46% | 27% | 9 h 50 min |
| January 13 | 59°F | 44°F | 46% | 27% | 9 h 50 min |
| January 14 | 59°F | 44°F | 46% | 27% | 9 h 50 min |
| January 15 | 60°F | 44°F | 46% | 27% | 9 h 50 min |
| January 16 | 60°F | 44°F | 46% | 27% | 9 h 50 min |
| January 17 | 60°F | 44°F | 46% | 27% | 9 h 50 min |
| January 18 | 60°F | 44°F | 46% | 27% | 9 h 50 min |
| January 19 | 60°F | 44°F | 46% | 27% | 10 h |
| January 20 | 60°F | 44°F | 46% | 27% | 10 h |
| January 21 | 60°F | 44°F | 46% | 27% | 10 h |
| January 22 | 60°F | 44°F | 46% | 28% | 10 h |
| January 23 | 60°F | 43°F | 46% | 28% | 10 h |
| January 24 | 60°F | 43°F | 46% | 28% | 10 h |
| January 25 | 60°F | 43°F | 46% | 28% | 10 h 10 min |
| January 26 | 60°F | 43°F | 46% | 28% | 10 h 10 min |
| January 27 | 60°F | 43°F | 46% | 28% | 10 h 10 min |
| January 28 | 60°F | 43°F | 46% | 28% | 10 h 10 min |
| January 29 | 60°F | 43°F | 46% | 28% | 10 h 10 min |
| January 30 | 60°F | 43°F | 46% | 28% | 10 h 10 min |
| January 31 | 60°F | 43°F | 46% | 28% | 10 h 20 min |
- Normal high
- 59°FJanuary average
- Normal low
- 43°FJanuary average
- Precipitation
- 5.07 inmonth total
- Days with precipitation
- 140.01 inch or more
- Nights at 32°F or colder
- 1
- Daylight
- 9 h 40 min to 10 h 20 minJanuary 1 to January 31
- Days at 70°F or more
- 1
- Sunshine
- 76%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00043714; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Half Moon Bay in January?
On a given January day the chance of 0.01 inch or more is 46% on average, highest around January 21 (46%). In all, 5.07 in falls on 14 days of a normal January, 2 of them with an inch or more.
In a normal January in Half Moon Bay, 1 nights fall to freezing.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00043714.
What are the records for January in Half Moon Bay?
The warmest January temperature on this station's record (since 1939) is 76°F, on January 23, 1948; the coldest is 27°F, on January 11, 1949. The wettest January brought 12.13 in (1998).
The January mean against the 1991-2020 normal of 51.4°F: 2021 51.0°F (−0.4), 2022 51.4°F (at normal), 2023 51.4°F (at normal), 2024 52.2°F (+0.8), 2025 50.1°F (−1.3), 2026 56.1°F (+4.7). 2 of 6 ran warmer than normal.
| January | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 51.0°F | −0.4°F | 2.88 in |
| 2022 | 51.4°F | at normal | 0.66 in |
| 2023 | 51.4°F | at normal | 8.55 in |
| 2024 | 52.2°F | +0.8°F | 6.04 in |
| 2025 | 50.1°F | −1.3°F | 0.40 in |
| 2026 | 56.1°F | +4.7°F | 4.77 in |
Source: records: ACIS, station USC00043714; recent months: ACIS, station USC00043714. Records and recent months use complete months only.
How does January in Half Moon Bay compare across California?
Across the 219 places PlainClimate covers in California, January normal highs run from 37°F in Tahoma to 72°F in Brawley; Half Moon Bay's is 59°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Half Moon Bay in December59°F by day, 43°F at night
- Half Moon Bay in February60°F by day, 43°F at night
- Half Moon Bay through the yearEvery month, frost dates, records and recent years
- California in JanuaryThe statewide normal and the warmest and coolest places
- Brawley: California's warmest Januarynormal high 72°F