Climate Comfort Score
78/100
Good
NOAA 1991–2020 normals 56°F annual avg Public-domain federal data
Hillsboro, IL Climate
Pulled from NOAA NCEI 1991–2020 normals →: average temperature, precipitation, and comfort score
- 56°F
- Avg annual temp
- 78/100
- Comfort score
- 42.1"
- Annual precip
- 194d
- Growing season
30-year climate normals from 1 weather station (1991-2020).
The climate verdict for Hillsboro
Hillsboro, Illinois averages 56°F a year and scores 78/100 on the comfort index - good, milder than 74% of U.S. cities.
- 56°F
- annual average temperature (NOAA normal)
- 78/100
- comfort score, milder than 74% of U.S. cities
- 42.1"
- precipitation, annual total
- 194 days
- frost-free days per growing season
Based on NOAA U.S. Climate Normals (1991–2020) - 30-year averages describing the typical year, not a forecast.
Avg Temperature
56°F (13°C)
Avg High
66°F
Avg Low
45°F
Annual Precip
42.1"
Comfort Score
78/100
Good
Avg Annual Temperature
56°F
30-year mean (NOAA NCEI)
Annual Precipitation
42.1"
Liquid-equivalent total
Comfort score vs national 100-point ceiling (Hillsboro) 78.0%
National median (63)
PlainClimate composite, temperature mildness, humidity, precipitation, extreme-weather frequency. Good for the Hillsboro area.
How Hillsboro compares to every U.S. city
Hillsboro's comfort score vs. all U.S. cities
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
78 Top 26% higher than 74% of 6,915 US cities
Each bar is a band; taller bars hold more US cities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Warming context for Hillsboro
MethodologyZooming out from Hillsboro's own normal, the chart below shows how the U.S. land temperature anomaly has tracked the global mean since 1900 - the most recent decade sits warmer than the 30-year mean shown here.
- United States land mean (NOAA NCEI) +0.11 °C/decade
- Global anomaly (NASA GISTEMP) +0.11 °C/decade
- Paris Agreement thresholds 1.5°C / 2.0°C
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 38°F (4°C) | 21°F (-6°C) | 30°F (-1°C) | 2.5" | 25.6 | 0.0 |
| February | 45°F (7°C) | 25°F (-4°C) | 35°F (2°C) | 2.6" | 20.4 | 0.0 |
| March | 55°F (13°C) | 34°F (1°C) | 45°F (7°C) | 3.0" | 13.7 | 0.0 |
| April | 68°F (20°C) | 44°F (7°C) | 56°F (13°C) | 5.0" | 3.4 | 0.1 |
| May | 78°F (25°C) | 54°F (12°C) | 66°F (19°C) | 5.1" | 0.0 | 1.5 |
| June | 86°F (30°C) | 63°F (17°C) | 75°F (24°C) | 3.8" | 0.0 | 10.7 |
| July | 89°F (32°C) | 67°F (19°C) | 78°F (25°C) | 3.7" | 0.0 | 14.3 |
| August | 87°F (31°C) | 65°F (18°C) | 76°F (24°C) | 3.1" | 0.0 | 10.5 |
| September | 82°F (28°C) | 57°F (14°C) | 69°F (21°C) | 3.3" | 0.1 | 5.0 |
| October | 70°F (21°C) | 46°F (8°C) | 58°F (14°C) | 3.4" | 2.5 | 0.3 |
| November | 55°F (13°C) | 35°F (2°C) | 45°F (7°C) | 3.8" | 11.8 | 0.0 |
| December | 43°F (6°C) | 26°F (-3°C) | 35°F (1°C) | 2.6" | 22.7 | 0.0 |
Monthly Precipitation
Average monthly rainfall
January 2.5"
6.3 days with precipitation
February 2.6"
6.3 days with precipitation
March 3.0"
8.4 days with precipitation
April 5.0"
9.6 days with precipitation
May 5.1"
11.2 days with precipitation
June 3.8"
8.6 days with precipitation
July 3.7"
7.3 days with precipitation
August 3.1"
6.6 days with precipitation
September 3.3"
5.9 days with precipitation
October 3.4"
7.3 days with precipitation
November 3.8"
6.6 days with precipitation
December 2.6"
6.8 days with precipitation
Frost Dates & Growing Season
First Fall Freeze
October 24
50% probability date
Last Spring Freeze
April 13
50% probability date
Growing Season
194 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,799
Higher = more heating needed
Cooling Degree Days
1,389
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
What Hillsboro's climate means for you
Hillsboro runs 56°F a year - peaking in July, coldest in January.
- Gardeners get about 194 frost-free days, with the last spring freeze near April 13 - plan the planting calendar around it, not the regional average.
- Energy bills track 4,799 heating and 1,389 cooling degree days a year, higher means the furnace or AC runs more.
- Comparing places to live? Line this city up against nearby cities and the national rankings. See rankings
These are 30-year NOAA normals (1991–2020) - the typical year, not a forecast for any specific season.
Climate Guides
Climate Insight: Hillsboro, IL
An annual average temperature of 56°F, ranging from a mean daily high of 66°F to a mean daily low of 45°F is what the NOAA 1991–2020 climate normals report for Hillsboro, Illinois. July is typically the warmest month of the year, while January is the coldest. That baseline comes from station USC00114108 and thirty years of averaging, so it reflects a typical month rather than any one year's swings.
Anyone planning to live, garden, or travel in Hillsboro should weigh precipitation alongside temperature: the annual average runs 42.1 inches, predominantly as rainfall. The frost-free season averages 194 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 13 and the first fall freeze near October 24. And on the energy front, 4,799 heating degree days and 1,389 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.
On PlainClimate's composite comfort index, Hillsboro scores 78/100 (Good), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. The monthly tables above are the practical planning tool: mild highs and lows land in the shoulder seasons, July-driven heat peaks in summer, and January-driven cold sets in over deep winter. These are thirty-year averages, not a forecast - any single year can run warmer, wetter, drier, or cooler than the normal.
Frequently Asked Questions
What is the average temperature in Hillsboro, IL? ▼
The average annual temperature in Hillsboro, Illinois is 56°F. The warmest month averages 89°F (32°C) and the coldest averages 21°F (-6°C).
How much rain does Hillsboro get? ▼
Hillsboro receives 42.1 inches of precipitation annually. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Hillsboro? ▼
Hillsboro has a climate comfort score of 78/100 (Good), milder than 74% of U.S. cities in the PlainClimate database.
When is the growing season in Hillsboro? ▼
Hillsboro has approximately 194 frost-free days per year, with the last spring freeze around April 13 and the first fall freeze around October 24.
How much energy does heating and cooling require in Hillsboro? ▼
Hillsboro has 4,799 heating degree days and 1,389 cooling degree days annually, a heating-dominated climate. See our <a href="/guides/reading-weather-data/" class="underline hover:text-brand-600">guide to reading weather data</a> for what these figures mean.
Where does this Hillsboro climate data come from? ▼
NOAA U.S. Climate Normals v1.0.1 (1991-2020), from weather station USC00114108 near Hillsboro.
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USC00114108. For informational purposes only.
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate Editorial
Every figure on PlainClimate is rendered directly from NOAA 1991-2020 U.S. Climate Normals data, no number is typed in by an editor. This page draws directly on NOAA 1991-2020 U.S. Climate Normals data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.