Marston Filter Plant, Colorado climate: Climate normals at a NOAA weather station
Marston Filter Plant's normal year runs from 19°F January nights to 86°F July afternoons, with 16.6 inches of precipitation and 34 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.4°C, January lows of −7°C, July highs of 30°C, 421 mm of precipitation a year.
- NOAA stationMarston Filter Plant
- Station IDUSC00055402
- Location39.62°N 105.07°W
- Elevation5,610 ft (1,710 m)
On October 23, the normal high in Marston Filter Plant is 62°F and the normal low 34°F, and the chance of measurable rain or snow is 15%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Marston Filter Plant.
- Jan 46° 19°
- Feb 47° 20°
- Mar 55° 28°
- Apr 60° 35°
- May 69° 44°
- Jun 81° 53°
- Jul 86° 60°
- Aug 85° 58°
- Sep 77° 49°
- Oct 64° 37°
- Nov 53° 28°
- Dec 45° 20°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Marston Filter Plant each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 19°F. The most precipitation falls in May (2.73 in), the least in January (0.48 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 46°F | 19°F | 32.6°F | 0.48 | 6.3 | 4 | <1 | 29 | 9 h 40 min |
| February | 47°F | 20°F | 33.4°F | 0.67 | 6.2 | 4 | <1 | 26 | 10 h 40 min |
| March | 55°F | 28°F | 41.3°F | 1.19 | 5.4 | 5 | <1 | 21 | 11 h 50 min |
| April | 60°F | 35°F | 47.3°F | 2.07 | 4.1 | 7 | <1 | 10 | 13 h 10 min |
| May | 69°F | 44°F | 56.4°F | 2.73 | 0.8 | 10 | 1 | 2 | 14 h 20 min |
| June | 81°F | 53°F | 67.1°F | 1.87 | 0.0 | 8 | 7 | <1 | 15 h |
| July | 86°F | 60°F | 73.0°F | 2.05 | 0.0 | 8 | 15 | <1 | 14 h 40 min |
| August | 85°F | 58°F | 71.3°F | 1.85 | 0.0 | 9 | 9 | <1 | 13 h 50 min |
| September | 77°F | 49°F | 63.0°F | 1.26 | 0.0 | 6 | 2 | <1 | 12 h 30 min |
| October | 64°F | 37°F | 50.4°F | 1.04 | 1.7 | 5 | <1 | 8 | 11 h 10 min |
| November | 53°F | 28°F | 40.6°F | 0.74 | 3.7 | 4 | <1 | 21 | 10 h |
| December | 45°F | 20°F | 32.8°F | 0.61 | 5.9 | 4 | <1 | 29 | 9 h 20 min |
| Year (annual) | 64°F | 38°F | 50.8°F | 16.56 | 34.1 | 74 | 33 | 147 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 8°C | −7°C | 0.3°C | 12 mm | 16 cm |
| February | 8°C | −6°C | 0.8°C | 17 mm | 16 cm |
| March | 13°C | −2°C | 5.2°C | 30 mm | 14 cm |
| April | 16°C | 1°C | 8.5°C | 53 mm | 10 cm |
| May | 21°C | 7°C | 13.6°C | 69 mm | 2 cm |
| June | 27°C | 12°C | 19.5°C | 47 mm | 0 cm |
| July | 30°C | 15°C | 22.8°C | 52 mm | 0 cm |
| August | 29°C | 14°C | 21.8°C | 47 mm | 0 cm |
| September | 25°C | 9°C | 17.2°C | 32 mm | 0 cm |
| October | 18°C | 3°C | 10.2°C | 26 mm | 4 cm |
| November | 12°C | −2°C | 4.8°C | 19 mm | 9 cm |
| December | 7°C | −7°C | 0.4°C | 15 mm | 15 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00055402; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Marston Filter Plant?
Normal highs sit between 65°F and 85°F in May, June, August and September. Of those, September has the fewest days with rain (6).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00055402.
When is the last frost at Marston Filter Plant?
In Marston Filter Plant, the last spring frost (32°F) comes after May 2 in half of years and after May 17 in one year in ten; the first autumn frost comes before October 11 in half of years and before September 27 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 21 year in 10 after May 17; 9 in 10 after April 20
- First autumn frost, half of years before
- October 111 year in 10 before September 27; 9 in 10 before October 23
NOAA puts the median frost-free season at 160 days, and the season without a hard freeze (28°F) at 180 days.
A hard freeze (28°F) comes after April 23 in half of springs and before October 21 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Marston Filter Plant in zone 6a in ZIP code 80123, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 6a: the coldest night of a typical year reaches −7°F (17 complete years).
Frost dates for every NOAA station in Colorado · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00055402; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Marston Filter Plant?
In a normal year in Marston Filter Plant, 33 days a year reach 90°F, 147 nights fall to 32°F or colder and 74 days bring measurable precipitation.
- Days at 90°F or more
- 33a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 147a normal year
- Days that stay below freezing
- 18high of 32°F or less
- Days with 0.01 inch of precipitation
- 74a normal year
- Days with 1 inch of snow or more
- 13a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00055402.
How sunny is it at Marston Filter Plant?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds at Marston Filter Plant, 4.7 kWh per square metre a day. February is the sunniest month (82%) and May the cloudiest (71%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 81% | 2.7 |
| February | 82% | 3.8 |
| March | 79% | 4.9 |
| April | 73% | 5.6 |
| May | 71% | 6.2 |
| June | 78% | 7.0 |
| July | 75% | 6.4 |
| August | 75% | 5.8 |
| September | 81% | 5.2 |
| October | 80% | 3.9 |
| November | 79% | 2.8 |
| December | 79% | 2.4 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Marston Filter Plant record?
A normal year at Marston Filter Plant brings 5,822 heating degree days, 8% more than the median U.S. place (5,373), and 659 cooling degree days, 27% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,772 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,006 | 0 |
| February | 885 | 0 |
| March | 733 | 0 |
| April | 532 | 1 |
| May | 284 | 17 |
| June | 58 | 121 |
| July | 5 | 251 |
| August | 12 | 206 |
| September | 124 | 62 |
| October | 452 | 2 |
| November | 734 | 0 |
| December | 998 | 0 |
| Year (annual) | 5,822 | 659 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00055402. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Have recent years at Marston Filter Plant been warmer than normal?
2025 averaged 51.8°F, 1.0°F above the 1991-2020 normal of 50.8°F. 2 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 52.0°F | +1.3°F | 16.74 | 57.3 |
| 2022 | 50.8°F | at normal | 15.66 | 71.9 |
| 2023 | 49.7°F | −1.1°F | 21.99 | 36.3 |
| 2025 | 51.8°F | +1.0°F | – | 37.5 |
Source: observed years: ACIS, station USC00055402. A year counts only with all twelve months complete.
How does Marston Filter Plant's climate compare?
Marston Filter Plant is warmer than 90 of the 125 places with their own NOAA record in Colorado, and wetter than 77. Across the 7,247 U.S. stations with normals, its annual mean of 50.8°F is warmer than 44%.
In the Köppen classification computed from these normals, Marston Filter Plant is BSk: cold semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Marston Filter Plant share this climate record?
8 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Littleton, CO44,879 people · 3 mi SE
- Englewood, CO35,238 people · 4 mi NE
- Dakota Ridge, CO34,159 people · 4 mi W
- Ken Caryl, CO33,407 people · 4 mi SW
- Columbine, CO25,681 people · 2 mi S
- Sheridan, CO5,932 people · 3 mi NE
- Columbine Valley, CO1,683 people · 2 mi SE
- Bow Mar, CO833 people · 1 mi NE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Marston Filter Plant's climate
What is the coldest month at Marston Filter Plant?
January, with a normal high of 46°F and a normal low of 19°F. The warmest is July (86°F by day, 60°F at night).
Does it snow at Marston Filter Plant?
Yes: 34 inches in a normal year, falling on 19 days with 0.1 inch or more, the most in January (6.3 inches).
What is the rainiest month at Marston Filter Plant?
May, with 2.73 in of precipitation in a normal year; the driest is January with 0.48 in.
What plant hardiness zone is Marston Filter Plant in?
The USDA's 2023 map puts Marston Filter Plant in zone 6a in ZIP code 80123, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −7°F (17 years, 1991-2020): zone 6a.
How late can frost come at Marston Filter Plant?
In half of years the last 32°F night comes after May 2; in one year in ten it comes after May 17. Waiting until May 17 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Colorado climateThe statewide normals and every place in the state
- Denver Water Dept, CO8 miles from this station, 53.3°F a year
- Kassler, CO9 miles from this station, 50.2°F a year
- Lakewood, CO9 miles from this station, 50.4°F a year
- Wheat Ridge, CO11 miles from this station, 50.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made