Jerome County, ID Climate: Temperature & Rain by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from Jerome County's primary NOAA station, JEROME CO AP.
The climate verdict for Jerome County
Dryness leads the climate profile for Jerome County, Idaho, with 9.9 inches of precipitation a year. NOAA records an annual average of 50°F. At 40/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 6% of scores.
- 50°F
- annual average temperature (NOAA normal)
- 40/100
- comfort score, above 6% of station-mapped location scores
- 9.9"
- precipitation, annual total
- 166 days
- frost-free growing season
Jerome County: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00004110 · Jerome County, ID 50°F mean · 9.9" precip
TEMP-COOL · RANK-MID · PHOTO-FINISH · PRCP-ARID · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 50°F
- RANK-MID #2,813
- PHOTO-FINISH ≈ Buhl
- PRCP-ARID 9.9"
- SWING-WIDE 45°F
- COMF-LOW 40/100
- LOAD-HEAT 6,073 HDD
- STN-1 USW00004110
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Buhl, ID (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every ID station list.
- Jerome County (this station) 50°F
- Cold Lawrence, MA 50°F
- Hot Niles, MI 50°F
- Near Buhl, ID 50°F
- Near Lock Haven Sewa…, PA 50°F
Climate Living Index · Jerome County
Jerome County: 35/100 · grade F
Jerome County publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Jerome County, not an official NOAA rating. Rankings still use Comfort Score 40/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 156 calendar days | 42/100 · D |
| Annual temperature balance | 50.2°F · 17.3° from 67.5°F | 41/100 · D |
| Frost-free season | 166 days/year | 38/100 · F |
| Precipitation balance | 9.9 in · 25.1 from 35 in | 12/100 · F |
Jerome County · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Jerome County's normals sit in a dry climate class: BSk
Precipitation is low relative to temperature but above true desert thresholds: cold semi-arid steppe (BSk). Class BSk is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically cold semi-arid steppe.
- Köppen code
- BSk
- Group
- Dry (arid or semi-arid)
- Warmest month
- 74.1°F
- Coldest month
- 29.1°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Jerome County sits across the climate record
Three NOAA fields for Jerome County's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 41st percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- Drier than 94%
- Jerome County's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- 59th percentile swing
- Typical seasonal amplitude versus 6,861 complete station-years.
How Jerome County compares across U.S. station-mapped locations
Jerome County's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
40 6th percentile score exceeds 6% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). This entry sits in this band.
- 50–60: 1,329 station-mapped locations (21%). Above this entry.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 36°F (2°C) | 23°F (-5°C) | 29°F (-2°C) | 1.2" | 29.0 | 0.0 |
| February | 41°F (5°C) | 25°F (-4°C) | 33°F (1°C) | 0.7" | 24.2 | 0.0 |
| March | 53°F (11°C) | 32°F (0°C) | 42°F (6°C) | 1.1" | 19.2 | 0.0 |
| April | 60°F (16°C) | 36°F (2°C) | 48°F (9°C) | 1.1" | 10.8 | 0.0 |
| May | 70°F (21°C) | 44°F (7°C) | 57°F (14°C) | 1.4" | 2.3 | 0.4 |
| June | 79°F (26°C) | 51°F (11°C) | 65°F (19°C) | 0.6" | 0.0 | 4.0 |
| July | 90°F (32°C) | 59°F (15°C) | 74°F (23°C) | 0.1" | 0.0 | 17.1 |
| August | 88°F (31°C) | 57°F (14°C) | 72°F (22°C) | 0.3" | 0.0 | 11.6 |
| September | 78°F (25°C) | 49°F (9°C) | 63°F (17°C) | 0.3" | 0.5 | 2.3 |
| October | 63°F (17°C) | 39°F (4°C) | 51°F (10°C) | 0.8" | 7.2 | 0.0 |
| November | 48°F (9°C) | 29°F (-2°C) | 38°F (4°C) | 1.0" | 20.6 | 0.0 |
| December | 36°F (2°C) | 23°F (-5°C) | 29°F (-1°C) | 1.3" | 28.3 | 0.0 |
The year, day by day
Jerome County works both ends of the calendar. Normal highs climb to 91°F by July 23 and hold at or above 90°F on 24 dates, then normal lows drop to freezing or below on 132 dates, bottoming at 22°F around December 23.
When the heat sits
Normal highs reach 90°F from July 14 through August 6, covering 24 dates. The broader mild season, normal highs of 70°F or more, runs May 17 to October 1.
This counts calendar dates whose 1991–2020 normal high reaches 90°F. It is a smaller number than the 90°F+ day counts in the monthly table above, which measure how often the threshold was actually crossed in a typical year. A date can average 88°F and still exceed 90°F in half of all years.
The freezing stretch
The normal low stays at or below 32°F into March 16, then returns to freezing around November 6, covering 132 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is December 22, when 33% of years recorded at least a hundredth of an inch. The driest is July 15 at 5%. Summed across the calendar, that is about 78 wet dates a year.
The widest day
July 20 carries the biggest normal gap between afternoon and dawn, 31°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Jerome County.
Where Jerome County Stands Nationally
Aridity defines the water calendar: about 10 inches in a normal year lands this among the driest tenth of ranked stations.
Jerome County earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall
9.2 days with precipitation
8.3 days with precipitation
9.1 days with precipitation
8.2 days with precipitation
7.9 days with precipitation
4.5 days with precipitation
1.5 days with precipitation
2.0 days with precipitation
3.6 days with precipitation
5.3 days with precipitation
7.5 days with precipitation
10.6 days with precipitation
Jerome County spreads its precipitation across the year
Neither half of the year dominates here: June through August take 10% of the annual total and December through February 33%, with neither reaching the 35% that would mark a distinct wet season. Jerome County has no dry season to plan around, though it does carry a wide 45°F gap between its warmest and coldest month.
The gap between the wettest and driest month still matters: May averages 1.4" and July 0.1". The three wettest months together take 40% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
Jerome County is dry, and what does fall arrives gently
Only about 78 days a year record measurable precipitation here, 21% of the calendar, and they carry 9.9" between them. At roughly 0.13 inches on an average wet day, this is not the damp drizzle of a marine climate; it is an arid record in which precipitation is both uncommon and light when it appears.
The wettest month by count is December at about 11 wet days; the driest is July at about 2.
A low per-event average in a dry record is a statement about typical days only. Arid regions can still take a large share of a year's total from a single convective storm, which a normal cannot show.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, not the extremes within it.
Frost Dates & Growing Season
First Fall Freeze
October 14
50% probability date
Last Spring Freeze
May 1
50% probability date
Growing Season
166 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
6,073
Higher = more heating needed
Cooling Degree Days
714
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside ID closest to Jerome County on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (50°F here).
- Ainsworth, NE 50°F · 0.0°F off
- Aurora, IL 50°F · 0.0°F off
- Blair, NE 50°F · 0.0°F off
- Bloomington, IL 50°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (9.9" here), excluding temperature-peer places.
- Fruita, CO 9.9" · 0.0" off
- Jeffrey City, WY 9.9" · 0.0" off
- Buena Vista, CO 9.9" · 0.0" off
- Woodruff, UT 9.9" · 0.0" off
Scarce-water calendar
Where Jerome County's limited precipitation lands
heating led · dry · mid swing
Jerome County's energy balance leans toward cold weather: 6,073 annual heating degree days against 714 for cooling. Its 45.0°F seasonal range still makes the monthly rows more useful than the annual average alone.
Jerome County's frost-free season lasts about 166 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
July and January mark the typical warm and cold ends of the calendar in Jerome County's middle-range seasonal profile. The measured spread is 45.0°F. The annual average is 50°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Jerome County's cold-season load does not imply a wet climate. Annual precipitation is 9.9 inches, which places the station in PlainClimate's dry range. Snowfall is not added to the interpretation because its annual value is missing. The snowfall and rainfall fields should be read separately rather than inferred from temperature.
Jerome County wettest normal
May
May concentrates the scarce annual total (9.9 inches).
Jerome County driest normal
July
July is typically driest; arid stations are defined by when water is absent, not by a four-season grid.
Questions about Jerome County's climate
How dry is Jerome County? ▼
How many days above 90°F does Jerome County get? ▼
How much energy does heating and cooling require in Jerome County? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Jerome County's primary station: JEROME CO AP (USW00004110). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The conservative exact name-and-state crosswalk finds no Census place match, so PlainClimate treats this as a station-mapped location and does not claim it is a municipality. No exact Gazetteer row for Jerome County; facility counts that depend on place identity are therefore an upper bound, not a municipal census.
On this page every temperature, precipitation, and derived score for Jerome County comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.