Thornton, CO weather in January
Thornton is chilly and mostly dry in January, with some snow: highs average 47°F and nights drop to about 18°F. Rain or snow falls on about 4 days. Snowfall averages about 6.4 in. This is the depth of winter in Thornton.
- Normal high
- 47°F
- Normal low
- 18°F
- Wet days
- 4
- 0.5 in total
- Snowfall
- 6.4 in
- snow on the ground 10 days
How January changes from start to finish
| January 1 | January 31 | |
|---|---|---|
| Normal high | 46°F | 46°F |
| Normal low | 17°F | 18°F |
| Chance of a wet day | 12% | 14% |
| Sunrise / sunset | 7:21 am / 4:45 pm | 7:08 am / 5:17 pm |
| Daylight | 9.4 h | 10.2 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Mountain Time).
A typical January day
- 6 am26°Fdew point 14°F
- 9 am31°Fdew point 15°F
- Noon40°Fdew point 16°F
- 3 pm41°Fdew point 16°F
- 6 pm33°Fdew point 16°F
- 9 pm29°Fdew point 16°F
NOAA hourly normals (local standard time) from Aurora Buckley Fld ANGB (16 mi away); average wind 8 mph; clear or few clouds in 36% of daytime hours, mostly cloudy or overcast in 48%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F2 of 31
- Hot dayshigh 90°F or more0 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow4 of 31
- Notable rainat least 0.10 in2 of 31
- Freezing nightslow 32°F or below30 of 31
- Snow on the groundsnow depth 1 in or more10 of 31
Average days per January, counted from daily records for each year 1991-2020.
Rain and snow in January
Normal precipitation is 0.5 in; a dry January brings about 0.1 in and a wet one about 0.7 in (25th and 75th percentiles). Days with half an inch or more are rare. Normal snowfall is 6.4 in, with about 2 days of an inch or more.
How January varies from year to year
- Warmest January, 1991-20202003: average high 53°F
- Coolest January2007: average high 35°F
- Wettest January2019: 1.6 in
- Driest January2003: no measurable precipitation
- Highest reading74°F (January 28, 2015)
- Lowest reading-12°F (January 7, 2017)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
January compared with December and February
| December | January | February | |
|---|---|---|---|
| Normal high | 46°F | 47°F | 48°F |
| Normal low | 18°F | 18°F | 19°F |
| Wet days | 4 | 4 | 4 |
| Comfortable days | 2 | 2 | 3 |
| Daylight | 9.4 h | 9.7 h | 10.7 h |
Highs change by +1°F from December and +1°F into February.
Nearby alternatives in January
- Cooler: Estes Park, CO46 mi · high 40°F · 6 wet days
How Thornton ranks in January
- Normal high211th warmest of 378 cities; 5th of 17 in Colorado
- Wet days22nd driest of 378
- Comfortable days184th most of 339
What to pack for Thornton in January
- A warm jacket – lows near 18°F, highs near 47°F
- Layers – afternoons near 47°F but nights near 18°F
- Waterproof boots – snow on the ground on about 10 days
- A hat and gloves – about 30 freezing nights
Heating and cooling
January has 1022 heating degree days and 0 cooling degree days (base 65°F), 16% of the year's total heating and cooling demand.
Questions
How cold is Thornton in January?
The normal high is 47°F and the normal low is 18°F. From 1991 to 2020 the coldest January reading was -12°F (most recently on January 7, 2017).
Does it rain a lot in Thornton in January?
About 4 days in January have at least 0.01 in of precipitation, and the normal total is 0.5 in. The wettest January in 1991-2020 was in 2019 (1.6 in); the driest was in 2003, with no measurable precipitation.
Does it snow in Thornton in January?
Yes. Normal snowfall in January is 6.4 in, and snow covers the ground on about 10 days.
Is January a good time to visit Thornton?
January ranks 11th of 12 months on our comfort score for Thornton (41 out of 100). It has about 2 comfortable days. The best month is May.
Where the numbers come from
- Temperature, snowfall and snow depth: Denver-Stapleton (USW00023062), 9.1 mi SE of the city center, 5,286 ft (61 ft lower than the city). NOAA normals and daily records, 1991-2020.
- Rain and frost dates: Northglenn (USC00055984), 3.1 mi NW of the city center, 5,407 ft (60 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Aurora Buckley Fld ANGB (USW00023036), 16 mi SE of the city center, 5,663 ft (316 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Denver International Airport (725650-03017), 17 mi E of the city center, 5,404 ft (57 ft higher than the city). Hourly observations, 1991-2020.