Fossil, Oregon climate: Normal weather by month, frost dates and records
Fossil's normal year runs from 24°F December nights to 85°F July afternoons, with 15.1 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.6°C, December lows of −4°C, July highs of 29°C, 382 mm of precipitation a year.
- NOAA stationFossil
- Station IDUSC00353038
- Location45.00°N 120.22°W
- Elevation2,650 ft (808 m)
- Population452
On October 23, the normal high in Fossil is 60°F and the normal low 32°F, and the chance of measurable rain or snow is 18%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fossil.
- Jan 42° 26°
- Feb 46° 26°
- Mar 52° 28°
- Apr 58° 31°
- May 66° 37°
- Jun 73° 42°
- Jul 85° 46°
- Aug 84° 45°
- Sep 74° 40°
- Oct 63° 33°
- Nov 48° 28°
- Dec 41° 24°
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 Fossil each month?
July is the warmest month, with normal highs of 85°F; December the coldest, with normal lows of 24°F. The most precipitation falls in May (2.12 in), the least in July (0.44 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 42°F | 26°F | 34.0°F | 1.40 | 5 | <1 | 21 | 9 h 10 min |
| February | 46°F | 26°F | 35.8°F | 1.17 | 5 | <1 | 19 | 10 h 20 min |
| March | 52°F | 28°F | 40.0°F | 1.51 | 6 | <1 | 19 | 11 h 50 min |
| April | 58°F | 31°F | 44.6°F | 1.35 | 5 | <1 | 13 | 13 h 30 min |
| May | 66°F | 37°F | 51.8°F | 2.12 | 6 | <1 | 5 | 14 h 50 min |
| June | 73°F | 42°F | 57.5°F | 1.32 | 4 | 2 | 1 | 15 h 40 min |
| July | 85°F | 46°F | 65.0°F | 0.44 | 2 | 12 | <1 | 15 h 20 min |
| August | 84°F | 45°F | 64.5°F | 0.58 | 2 | 10 | <1 | 14 h 10 min |
| September | 74°F | 40°F | 57.1°F | 0.55 | 2 | 3 | 2 | 12 h 40 min |
| October | 63°F | 33°F | 48.1°F | 1.47 | 5 | <1 | 10 | 11 h |
| November | 48°F | 28°F | 38.3°F | 1.38 | 6 | <1 | 16 | 9 h 40 min |
| December | 41°F | 24°F | 32.5°F | 1.76 | 4 | <1 | 21 | 8 h 50 min |
| Year (annual) | 61°F | 34°F | 47.4°F | 15.05 | 52 | 27 | 127 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 6°C | −3°C | 1.1°C | 36 mm |
| February | 8°C | −4°C | 2.1°C | 30 mm |
| March | 11°C | −2°C | 4.4°C | 38 mm |
| April | 14°C | 0°C | 7.0°C | 34 mm |
| May | 19°C | 3°C | 11.0°C | 54 mm |
| June | 23°C | 5°C | 14.2°C | 34 mm |
| July | 29°C | 8°C | 18.3°C | 11 mm |
| August | 29°C | 7°C | 18.1°C | 15 mm |
| September | 24°C | 4°C | 13.9°C | 14 mm |
| October | 17°C | 1°C | 8.9°C | 37 mm |
| November | 9°C | −2°C | 3.5°C | 35 mm |
| December | 5°C | −4°C | 0.3°C | 45 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Condon (17 miles away), gets 26 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00353038; 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 Fossil?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, August has the fewest days with rain (2).
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 USC00353038.
When is the last frost in Fossil?
In Fossil, the last spring frost (32°F) comes after June 3 in half of years and after July 3 in one year in ten; the first autumn frost comes before September 14 in half of years and before August 25 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
- June 31 year in 10 after July 3; 9 in 10 after May 13
- First autumn frost, half of years before
- September 141 year in 10 before August 25; 9 in 10 before October 3
NOAA puts the median frost-free season at 98 days, and the season without a hard freeze (28°F) at 142 days.
A hard freeze (28°F) comes after May 10 in half of springs and before October 2 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fossil in zone 7a in ZIP code 97830, the nearest ZIP area.
Frost dates for every NOAA station in Oregon · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00353038; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Fossil?
In a normal year in Fossil, 27 days a year reach 90°F (3 of them 100°F or more), 127 nights fall to 32°F or colder and 52 days bring measurable precipitation.
- Days at 90°F or more
- 27a normal year
- Days at 100°F or more
- 3a normal year
- Nights at 32°F or colder
- 127a normal year
- Days that stay below freezing
- 10high of 32°F or less
- Days with 0.01 inch of precipitation
- 52a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00353038.
How sunny is Fossil?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fossil, 4.4 kWh per square metre a day. July is the sunniest month (93%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 1.6 |
| February | 68% | 2.5 |
| March | 69% | 3.7 |
| April | 73% | 5.2 |
| May | 76% | 6.3 |
| June | 83% | 7.3 |
| July | 93% | 7.8 |
| August | 91% | 6.6 |
| September | 87% | 5.0 |
| October | 78% | 3.2 |
| November | 67% | 1.9 |
| December | 62% | 1.3 |
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 Fossil need?
A normal year in Fossil brings 6,565 heating degree days, 22% more than the median U.S. place (5,373), and 174 cooling degree days, 81% 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 1,603 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 961 | 0 |
| February | 818 | 0 |
| March | 775 | 0 |
| April | 612 | 0 |
| May | 412 | 3 |
| June | 242 | 15 |
| July | 80 | 80 |
| August | 83 | 66 |
| September | 247 | 10 |
| October | 524 | 0 |
| November | 802 | 0 |
| December | 1,009 | 0 |
| Year (annual) | 6,565 | 174 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00353038. 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 Fossil been warmer than normal lately?
2024 averaged 49.1°F, 1.8°F above the 1991-2020 normal of 47.4°F. 3 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 49.8°F | +2.4°F | 10.56 |
| 2023 | 48.9°F | +1.5°F | – |
| 2024 | 49.1°F | +1.8°F | 16.02 |
Source: observed years: ACIS, station USC00353038. A year counts only with all twelve months complete.
How does Fossil's climate compare?
Fossil is warmer than 14 of the other 104 places with their own NOAA record in Oregon, and wetter than 29. Across the 7,247 U.S. stations with normals, its annual mean of 47.4°F is warmer than 29%.
In the Köppen classification computed from these normals, Fossil is Csb: temperate, dry-summer, warm summer. 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 Fossil share this climate record?
Lonerock 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.
- Lonerock, OR21 people · 17 mi E
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 Fossil's climate
What is the coldest month in Fossil?
December, with a normal high of 41°F and a normal low of 24°F. The warmest is July (85°F by day, 46°F at night).
Does it snow in Fossil?
Yes. NOAA publishes no 1991-2020 snowfall normal for Fossil's NOAA station; the nearest record that keeps one, Condon (17 miles away), records 26 inches of snow in a normal year.
What is the rainiest month in Fossil?
May, with 2.12 in of precipitation in a normal year; the driest is July with 0.44 in.
What plant hardiness zone is Fossil in?
The USDA's 2023 map puts Fossil in zone 7a in ZIP code 97830, the nearest ZIP area.
How late can frost come in Fossil?
In half of years the last 32°F night comes after June 3; in one year in ten it comes after July 3. Waiting until July 3 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Oregon climateThe statewide normals and every place in the state
- Condon, OR17 miles from this station, 49.0°F a year
- Kent, OR27 miles from this station, 49.4°F a year
- Antelope, OR29 miles from this station, 49.3°F a year
- Mitchell, OR30 miles from this station, 48.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made