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Greeley weather by month: averages, rainfall & climate trends

Seasons run to extremes in Greeley: monthly means span 47.9°F between the coldest month and the warmest. This is a dry climate by most measures, though not a rainless one. Greeley weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

−12.9°Fhigh well below average

50° / 43°Today
63° / 36°Average
see today in detail →

How it's changed

+6.0°Faverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49122frost days a year now (2016–2025) · 159 in the 1940sfrost days a year · 159 in the 1940s87days above 86°F a year now (2016–2025) · 53 in the 1940sdays above 86°F · 53 in the 1940s+6.0°F vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 0.6 incheshigh 41°low 18°February, rain 0.6 incheshigh 45°low 21°March, rain 1.4 incheshigh 55°low 28°April, rain 2.1 incheshigh 64°low 36°May, rain 2.9 incheshigh 73°low 46°June, rain 1.9 incheshigh 83°low 55°July, rain 1.5 incheshigh 90°low 62°August, rain 1.4 incheshigh 88°low 60°September, rain 1.2 incheshigh 80°low 52°October, rain 1.1 incheshigh 67°low 40°November, rain 0.8 incheshigh 51°low 28°December, rain 0.6 incheshigh 42°low 21°wettest month May, 2.9 inches · 16.1 inches a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Overcast

Right now

43.5°

40°feels like
95%humidity
42°dew point
4 mphfrom E
UV index0.0
sunrise07:22sunset18:03day length10h 41m
TodayOvercast50°43°
TueClear61°41°
WedOvercast72°46°
ThuOvercast65°45°
FriOvercast64°46°
SatClear69°46°
SunOvercast66°48°

On this date: October 26

Today (forecast)
50° / 43°
Average for October 26
63° / 36°

High well below average · −12.9°F

  • Highest since 1940: 79.5° · 1977
  • Lowest since 1940: 8.9° · 2020
  • One year ago: 66° / 43°

Every October 26 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 26 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Greeley is sampled from the ECMWF ERA5 reanalysis at 40.42°N, 104.71°W, with daily records since 1940.

Coordinates
40.42°N, 104.71°W
Time zone
America/Denver
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

26 of the last 31 days were warmer than the historical average for that date. Average difference: +8.0°F.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

The warmest month is July, with typical afternoon highs of 89.8°F and nights around 61.7°F. The coolest month is January, when afternoons reach about 40.6°F and overnight lows sit around 18.0°F. Frost shows up on around 120 mornings a year.

The yearly total for Greeley comes to about 16.1 inches; monthly amounts range from 0.6 inches in December up to 2.9 inches in May.

Comparing the record's first decade with its most recent one, Greeley now averages 6.0°F warmer than it did in the 1940s. The count of days past 86°F has risen from roughly 55 a year to 85 between the record's first and last decades.

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 48°F. Wettest month: May (~2.9 in). Whole year averages ~16.1 inches of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 48 rainy days a year: most in May (~7), fewest in January (~2).

Bars = average number of days with ≥ 0.08 in per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Greeley month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightHighestLowest
January40.6°18.0°0.6 in29.4 h71.5° (2015)−24.9° (1942)
February45.5°21.1°0.6 in210.5 h75.9° (2017)−27.6° (1996)
March54.7°27.7°1.4 in511.7 h82.6° (2015)−22.2° (1948)
April64.2°36.4°2.1 in613.1 h88.9° (1992)−2.4° (1945)
May72.7°46.2°2.9 in714.2 h96.1° (2003)19.4° (1979)
June83.4°55.4°1.9 in514.9 h103.8° (1954)33.0° (1947)
July89.8°61.7°1.5 in514.6 h104.9° (1954)47.6° (1971)
August87.8°60.2°1.4 in413.6 h102.2° (1979)44.2° (1968)
September80.1°51.5°1.2 in312.3 h100.8° (2019)18.8° (1985)
October67.2°39.8°1.1 in310.9 h89.8° (2024)−4.3° (2020)
November51.4°27.8°0.8 in39.7 h78.3° (2025)−9.7° (1955)
December42.2°20.7°0.6 in29.1 h74.3° (2025)−32.4° (1990)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +6.0°F.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.55°F per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Mar–May is warming fastest: +0.76°F per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 86°F per year: 53.4 early in the record → 86.8 recently. Frost days: 159 → 122.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 1954, coldest in 1990: 104.9°F / −32.4°F.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~16.1 in/year on average. Last decade: −10% vs that average. Long-term trend: −0.24 in per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Greeley

Which is the warmest month in Greeley?
On long-term average, the warmest month in Greeley is July (mean daily temperature of about 74.9°F) and the coolest is January (about 27.0°F).
How does today's temperature in Greeley compare to the historical average?
On October 26, 2026, Greeley is forecast to reach a high of 50.4°F and a low of 43.2°F. The long-term average for this date (the full record since 1940) is a high of 63.3°F and a low of 35.9°F, so today's high is 12.9°F cooler than that average.
How much has Greeley warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Greeley is about 6.0°F warmer.
How much does it rain in Greeley?
Greeley receives about 16.1 inches of precipitation per year on long-term average, with May typically the wettest month.
What is the average temperature in Greeley?
Over the full record (since 1940), the annual mean temperature in Greeley is about 50.2°F. The warmest month is July and the coolest is January.
What are the average temperatures in Greeley by month?
Average daily highs and lows for each month in Greeley (°F, full record since 1940): January 41°/18°, February 45°/21°, March 55°/28°, April 64°/36°, May 73°/46°, June 83°/55°, July 90°/62°, August 88°/60°, September 80°/52°, October 67°/40°, November 51°/28°, December 42°/21°.
What is the weather like in Greeley in summer?
Summer in Greeley (June to August) is hot. Afternoons run 83–90°F and nights 55–62°F; July is the warmest month. Rain falls on about 5 days a month, adding up to around 1.6 inches.
What is the weather like in Greeley in winter?
In winter, December through February, Greeley is dry and cold. Expect 41–45°F by day and 18–21°F at night, with January the coldest month. Rain is steady at around 0.6 inches a month, spread over roughly 2 days. No season is drier.
What is the weather like in Greeley in spring?
March to May is spring in Greeley, and it is fairly mild. March is still 55°F in the afternoon and 28°F at night, May already 73°F and 46°F. Rain picks up through the season: 5 rainy days and 1.4 inches in March, 7 days and 2.9 inches in May. It is the wettest season of the year.
What is the weather like in Greeley in autumn?
Autumn in Greeley (September to November) is mild. September is still 80°F by day and 52°F at night; by November it is down to 51°F and 28°F. Rain is steady at around 1.0 inches a month, spread over roughly 3 days.
How many days a year does it rain in Greeley?
On long-term average, Greeley has about 48 days a year with at least 0.08 inches of rain or snow. The annual total is roughly 16.1 inches.

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