Riddle, Oregon climate: Normal weather by month, frost dates and records
Riddle's normal year runs from 37°F December nights to 88°F July afternoons, with 31.1 inches of precipitation and 2 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.7°C, December lows of 3°C, July highs of 31°C, 789 mm of precipitation a year.
- NOAA stationRiddle
- Station IDUSC00357169
- Location42.95°N 123.36°W
- Elevation680 ft (207 m)
- Population1,220
On October 23, the normal high in Riddle is 68°F and the normal low 43°F, and the chance of measurable rain or snow is 43%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Riddle.
- Jan 53° 37°
- Feb 57° 37°
- Mar 62° 39°
- Apr 66° 41°
- May 74° 47°
- Jun 80° 51°
- Jul 88° 55°
- Aug 89° 54°
- Sep 84° 49°
- Oct 71° 43°
- Nov 58° 41°
- Dec 51° 37°
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 Riddle each month?
July is the warmest month, with normal highs of 88°F; December the coldest, with normal lows of 37°F. The most precipitation falls in December (6.17 in), the least in July (0.27 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 53°F | 37°F | 44.8°F | 4.72 | 0.5 | 19 | <1 | 8 | 9 h 20 min |
| February | 57°F | 37°F | 47.2°F | 3.35 | 0.7 | 17 | <1 | 6 | 10 h 30 min |
| March | 62°F | 39°F | 50.2°F | 3.39 | 0.1 | 18 | <1 | 5 | 11 h 50 min |
| April | 66°F | 41°F | 53.8°F | 2.53 | 0.0 | 16 | <1 | 1 | 13 h 20 min |
| May | 74°F | 47°F | 60.1°F | 1.86 | 0.0 | 12 | 1 | <1 | 14 h 40 min |
| June | 80°F | 51°F | 65.3°F | 0.98 | 0.0 | 6 | 3 | <1 | 15 h 20 min |
| July | 88°F | 55°F | 71.7°F | 0.27 | 0.0 | 2 | 12 | <1 | 15 h |
| August | 89°F | 54°F | 71.4°F | 0.28 | 0.0 | 2 | 12 | <1 | 14 h |
| September | 84°F | 49°F | 66.0°F | 0.71 | 0.0 | 5 | 7 | <1 | 12 h 30 min |
| October | 71°F | 43°F | 57.1°F | 2.25 | 0.0 | 12 | 1 | 2 | 11 h 10 min |
| November | 58°F | 41°F | 49.3°F | 4.57 | 0.0 | 19 | <1 | 4 | 9 h 50 min |
| December | 51°F | 37°F | 43.7°F | 6.17 | 0.6 | 20 | <1 | 7 | 9 h |
| Year (annual) | 69°F | 44°F | 56.7°F | 31.08 | 1.9 | 147 | 35 | 33 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 12°C | 3°C | 7.1°C | 120 mm | 1 cm |
| February | 14°C | 3°C | 8.4°C | 85 mm | 2 cm |
| March | 16°C | 4°C | 10.1°C | 86 mm | 0 cm |
| April | 19°C | 5°C | 12.1°C | 64 mm | 0 cm |
| May | 23°C | 8°C | 15.6°C | 47 mm | 0 cm |
| June | 26°C | 11°C | 18.5°C | 25 mm | 0 cm |
| July | 31°C | 13°C | 22.1°C | 7 mm | 0 cm |
| August | 32°C | 12°C | 21.9°C | 7 mm | 0 cm |
| September | 29°C | 9°C | 18.9°C | 18 mm | 0 cm |
| October | 22°C | 6°C | 13.9°C | 57 mm | 0 cm |
| November | 14°C | 5°C | 9.6°C | 116 mm | 0 cm |
| December | 10°C | 3°C | 6.5°C | 157 mm | 2 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00357169; 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 Riddle?
Normal highs sit between 65°F and 85°F in April, May, June, September and October. Of those, September has the fewest days with rain (5).
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 USC00357169.
When is the last frost in Riddle?
In Riddle, the last spring frost (32°F) comes after March 31 in half of years and after April 27 in one year in ten; the first autumn frost comes before November 6 in half of years and before October 11 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
- March 311 year in 10 after April 27; 9 in 10 after February 27
- First autumn frost, half of years before
- November 61 year in 10 before October 11; 9 in 10 before December 13
NOAA puts the median frost-free season at 221 days, and the season without a hard freeze (28°F) at 292 days.
A hard freeze (28°F) comes after February 20 in half of springs and before December 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Riddle in zone 8b in ZIP code 97469, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Riddle's NOAA station is in zone 9a: the coldest night of a typical year reaches 22°F (26 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 Oregon · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00357169; 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 Riddle?
In a normal year in Riddle, 35 days a year reach 90°F (3 of them 100°F or more), 33 nights fall to 32°F or colder and 147 days bring measurable precipitation.
- Days at 90°F or more
- 35a normal year
- Days at 100°F or more
- 3a normal year
- Nights at 32°F or colder
- 33a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 147a normal year
- Days with 1 inch of snow or more
- 1a normal year
The highest temperature in this station's record (since 1899) is 111°F, on June 28, 2021; the lowest is 2°F, on January 23, 1962.
The wettest calendar year on that record is 1996, with 54.80 in; the snowiest season is 1949–50, with 43.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00357169; records: ACIS (NOAA Regional Climate Centers), station USC00357169. Records use complete months only; a month missing more than three days is left out.
How sunny is Riddle?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Riddle, 4.5 kWh per square metre a day. July is the sunniest month (94%) and December the cloudiest (58%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 1.7 |
| February | 66% | 2.6 |
| March | 66% | 3.6 |
| April | 71% | 5.0 |
| May | 78% | 6.4 |
| June | 84% | 7.4 |
| July | 94% | 7.9 |
| August | 93% | 6.8 |
| September | 88% | 5.2 |
| October | 79% | 3.4 |
| November | 65% | 1.9 |
| December | 58% | 1.4 |
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 much heating and cooling does Riddle need?
A normal year in Riddle brings 3,630 heating degree days, 32% fewer than the median U.S. place (5,373), and 628 cooling degree days, 31% fewer than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,153 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 626 | 0 |
| February | 500 | 0 |
| March | 460 | 0 |
| April | 339 | 3 |
| May | 179 | 27 |
| June | 66 | 75 |
| July | 7 | 216 |
| August | 8 | 206 |
| September | 59 | 90 |
| October | 253 | 10 |
| November | 471 | 0 |
| December | 662 | 0 |
| Year (annual) | 3,630 | 628 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00357169. 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 Riddle been warmer than normal lately?
2024 averaged 57.4°F, 0.7°F above the 1991-2020 normal of 56.7°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 57.3°F | +0.6°F | 27.21 | 10.8 |
| 2022 | 57.1°F | +0.4°F | 26.46 | 0.0 |
| 2023 | 56.8°F | +0.1°F | 27.74 | 2.3 |
| 2024 | 57.4°F | +0.7°F | 41.19 | 2.3 |
Over 91 complete years from 1893 to 2024, the station's annual mean temperature rose at a fitted 2.8°F per century (+0.15°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00357169; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Riddle's climate compare?
Riddle is warmer than 104 of the other 104 places with their own NOAA record in Oregon, and wetter than 45. Across the 7,247 U.S. stations with normals, its annual mean of 56.7°F is warmer than 66%.
In the Köppen classification computed from these normals, Riddle is Csa: temperate, dry-summer, hot 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 Riddle share this climate record?
4 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.
- Tri-City, OR4,362 people · 4 mi NE
- Myrtle Creek, OR3,498 people · 6 mi NE
- Canyonville, OR1,664 people · 4 mi E
- Days Creek, OR148 people · 10 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 Riddle's climate
What is the coldest month in Riddle?
December, with a normal high of 51°F and a normal low of 37°F. The warmest is July (88°F by day, 55°F at night).
Does it snow in Riddle?
Yes: 2 inches in a normal year, falling on 1 days with 0.1 inch or more, the most in February (0.7 inches).
What is the rainiest month in Riddle?
December, with 6.17 in of precipitation in a normal year; the driest is July with 0.27 in.
What plant hardiness zone is Riddle in?
The USDA's 2023 map puts Riddle in zone 8b in ZIP code 97469, the nearest ZIP area. By the same method at Riddle's NOAA station, the coldest night of a typical year reaches 22°F (26 years, 1991-2020): zone 9a.
How late can frost come in Riddle?
In half of years the last 32°F night comes after March 31; in one year in ten it comes after April 27. Waiting until April 27 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Oregon climateThe statewide normals and every place in the state
- Roseburg, OR20 miles from this station, 55.9°F a year
- Winchester, OR23 miles from this station, 54.9°F a year
- Sexton Summit, OR24 miles from this station, 48.9°F a year
- Idleyld Park (4 mi NE), OR35 miles from this station, 52.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made