Glendo, Wyoming climate: Normal weather by month, frost dates and records
Glendo's normal year runs from 15°F January nights to 88°F July afternoons, with 14.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.8°C, January lows of −10°C, July highs of 31°C, 367 mm of precipitation a year.
- NOAA stationGlendo Reservoir USBR
- Station IDUSC00483944
- Location42.47°N 104.97°W
- Elevation4,780 ft (1,457 m)
- From the center4 miles
- Population238
On October 23, the normal high in Glendo is 58°F and the normal low 31°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Glendo.
- Jan 39° 15°
- Feb 40° 16°
- Mar 50° 25°
- Apr 58° 32°
- May 67° 42°
- Jun 79° 52°
- Jul 88° 59°
- Aug 86° 57°
- Sep 77° 47°
- Oct 61° 34°
- Nov 48° 23°
- Dec 38° 16°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Glendo each month?
July is the warmest month, with normal highs of 88°F; January the coldest, with normal lows of 15°F. The most precipitation falls in May (2.81 in), the least in January (0.37 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 39°F | 15°F | 26.9°F | 0.37 | – | <1 | 29 | 9 h 20 min |
| February | 40°F | 16°F | 27.7°F | 0.42 | – | <1 | 26 | 10 h 30 min |
| March | 50°F | 25°F | 37.2°F | 0.90 | – | <1 | 21 | 11 h 50 min |
| April | 58°F | 32°F | 44.8°F | 1.91 | – | <1 | 13 | 13 h 20 min |
| May | 67°F | 42°F | 54.5°F | 2.81 | – | <1 | 3 | 14 h 30 min |
| June | 79°F | 52°F | 65.4°F | 1.95 | – | 6 | <1 | 15 h 20 min |
| July | 88°F | 59°F | 73.4°F | 1.52 | – | 13 | <1 | 15 h |
| August | 86°F | 57°F | 71.3°F | 1.16 | – | 10 | <1 | 14 h |
| September | 77°F | 47°F | 61.9°F | 1.15 | – | 3 | 1 | 12 h 30 min |
| October | 61°F | 34°F | 47.7°F | 1.23 | – | <1 | 12 | 11 h 10 min |
| November | 48°F | 23°F | 35.9°F | 0.47 | – | <1 | 24 | 9 h 50 min |
| December | 38°F | 16°F | 27.0°F | 0.54 | – | <1 | 29 | 9 h 10 min |
| Year (annual) | 61°F | 35°F | 47.8°F | 14.43 | – | 32 | 158 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 4°C | −10°C | −2.8°C | 9 mm |
| February | 4°C | −9°C | −2.4°C | 11 mm |
| March | 10°C | −4°C | 2.9°C | 23 mm |
| April | 14°C | 0°C | 7.1°C | 49 mm |
| May | 20°C | 5°C | 12.5°C | 71 mm |
| June | 26°C | 11°C | 18.6°C | 50 mm |
| July | 31°C | 15°C | 23.0°C | 39 mm |
| August | 30°C | 14°C | 21.8°C | 29 mm |
| September | 25°C | 8°C | 16.6°C | 29 mm |
| October | 16°C | 1°C | 8.7°C | 31 mm |
| November | 9°C | −5°C | 2.2°C | 12 mm |
| December | 3°C | −9°C | −2.8°C | 14 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Glendo's own co-op station Glendo (6 mi NE) does: 44 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USC00483944; 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.
When is the best weather to visit Glendo?
Normal highs sit between 65°F and 85°F in May, June and September.
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 USC00483944.
When is the last frost in Glendo?
In Glendo, the last spring frost (32°F) comes after May 9 in half of years and after May 24 in one year in ten; the first autumn frost comes before October 5 in half of years and before September 21 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 91 year in 10 after May 24; 9 in 10 after April 27
- First autumn frost, half of years before
- October 51 year in 10 before September 21; 9 in 10 before October 17
NOAA puts the median frost-free season at 148 days, and the season without a hard freeze (28°F) at 167 days.
A hard freeze (28°F) comes after April 29 in half of springs and before October 14 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Glendo in zone 5a in ZIP code 82213, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Glendo's NOAA station is in zone 4a: the coldest night of a typical year reaches −26°F (15 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Wyoming · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00483944; 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 in Glendo?
In a normal year in Glendo, 32 days a year reach 90°F (1 of them 100°F or more) and 158 nights fall to 32°F or colder.
- Days at 90°F or more
- 32a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 158a normal year
- Days that stay below freezing
- 37high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00483944.
How sunny is Glendo?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Glendo, 4.5 kWh per square metre a day. July is the sunniest month (86%) and February the cloudiest (72%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 2.1 |
| February | 72% | 2.9 |
| March | 73% | 4.2 |
| April | 72% | 5.2 |
| May | 74% | 6.2 |
| June | 82% | 7.2 |
| July | 86% | 7.1 |
| August | 86% | 6.3 |
| September | 84% | 5.0 |
| October | 77% | 3.4 |
| November | 76% | 2.4 |
| December | 72% | 1.8 |
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 much heating and cooling does Glendo need?
A normal year in Glendo brings 6,882 heating degree days, 28% more than the median U.S. place (5,373), and 632 cooling degree days, 30% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,566 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,183 | 0 |
| February | 1,046 | 0 |
| March | 864 | 0 |
| April | 608 | 0 |
| May | 339 | 12 |
| June | 75 | 85 |
| July | 5 | 263 |
| August | 19 | 212 |
| September | 152 | 57 |
| October | 539 | 2 |
| November | 875 | 0 |
| December | 1,179 | 0 |
| Year (annual) | 6,882 | 632 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00483944. 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.
Has Glendo been warmer than normal lately?
2025 averaged 49.9°F, 2.1°F above the 1991-2020 normal of 47.8°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 49.0°F | +1.2°F | 6.93 |
| 2022 | 47.9°F | +0.1°F | 5.34 |
| 2023 | 47.4°F | −0.4°F | – |
| 2025 | 49.9°F | +2.1°F | 7.98 |
Source: observed years: ACIS, station USC00483944. A year counts only with all twelve months complete.
How does Glendo's climate compare?
Glendo is warmer than 61 of the other 70 places with their own NOAA record in Wyoming, and wetter than 41. Across the 7,247 U.S. stations with normals, its annual mean of 47.8°F is warmer than 31%.
In the Köppen classification computed from these normals, Glendo 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 Glendo share this climate record?
Lost Springs has no NOAA station with 1991-2020 normals of its 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.
- Lost Springs, WY4 people · 21 mi N
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Glendo's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Glendo. This page uses Glendo Reservoir USBR; the other differs by site and elevation:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Glendo (6 mi NE) USC00483936 | 6 mi E | 4,739 ft | 44.7°F | 7°F | 87°F | 13.4 | 44 | May 25 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Glendo's climate
What is the coldest month in Glendo?
January, with a normal high of 39°F and a normal low of 15°F. The warmest is July (88°F by day, 59°F at night).
Does it snow in Glendo?
Yes. NOAA publishes no 1991-2020 snowfall normal for Glendo's NOAA station; Glendo's own co-op station Glendo (6 mi NE) records 44 inches of snow in a normal year.
What is the rainiest month in Glendo?
May, with 2.81 in of precipitation in a normal year; the driest is January with 0.37 in.
What plant hardiness zone is Glendo in?
The USDA's 2023 map puts Glendo in zone 5a in ZIP code 82213, the nearest ZIP area. By the same method at Glendo's NOAA station, the coldest night of a typical year reaches −26°F (15 years, 1991-2020): zone 4a.
How late can frost come in Glendo?
In half of years the last 32°F night comes after May 9; in one year in ten it comes after May 24. Waiting until May 24 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wyoming climateThe statewide normals and every place in the state
- Guernsey, WY16 miles from this station, 48.7°F a year
- Whalen Dam USBR, WY23 miles from this station, 48.1°F a year
- Wheatland, WY25 miles from this station, 49.0°F a year
- Old Fort Laramie, WY28 miles from this station, 49.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made