The best times to visit Fairfax for ideal weather are
May 14th to October 7th
based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.
Fairfax Travel Guide
Other Fairfax Travel Info
Weather in Fairfax
Temperature
Average temperatures in Fairfax vary an incredible amount. Considering humidity, temperatures feel cold for about half of the year and otherwise nice with a very low chance of rain or snow throughout the year. The area is somewhat temperate — in the 45th percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit Fairfax, the hottest months are July, August, and then June. See average monthly temperatures below. The warmest time of year is generally mid July where highs are regularly around 89.5°F (31.9°C) with temperatures rarely dropping below 64.1°F (17.8°C) at night.
Fairfax Temperatures (Fahrenheit)
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Fairfax Temperatures (Celsius)
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“Feels-Like” Temperatures
The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.
Fairfax Perceived Temperature (F)
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Fairfax Perceived Temperature (C)
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Average Fairfax Temperatures by Month
Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.
Show Fahrenheit
| Month | Avg. High (°F) | Avg. Mean (°F) | Avg. Low (°F) |
|---|---|---|---|
| Jan | 34.8 | 23.2 | 13.9 |
| Feb | 36.3 | 24.2 | 15.2 |
| Mar | 52.6 | 38.3 | 28.1 |
| Apr | 61.4 | 47.7 | 36.9 |
| May | 71.5 | 58.5 | 47.6 |
| Jun | 80.8 | 68.7 | 58 |
| Jul | 87.8 | 74.8 | 62.8 |
| Aug | 84.7 | 72 | 61.2 |
| Sep | 78.2 | 63.5 | 51.5 |
| Oct | 63.8 | 49.9 | 39.1 |
| Nov | 50.9 | 37.1 | 26.4 |
| Dec | 34.8 | 24.1 | 15.4 |
Show Celsius
| Month | Avg. High (°C) | Avg. Mean (°C) | Avg. Low (°C) |
|---|---|---|---|
| Jan | 1.6 | -4.9 | -10.1 |
| Feb | 2.4 | -4.3 | -9.3 |
| Mar | 11.4 | 3.5 | -2.2 |
| Apr | 16.3 | 8.7 | 2.7 |
| May | 21.9 | 14.7 | 8.7 |
| Jun | 27.1 | 20.4 | 14.4 |
| Jul | 31 | 23.8 | 17.1 |
| Aug | 29.3 | 22.2 | 16.2 |
| Sep | 25.7 | 17.5 | 10.8 |
| Oct | 17.7 | 9.9 | 3.9 |
| Nov | 10.5 | 2.8 | -3.1 |
| Dec | 1.6 | -4.4 | -9.2 |
Precipitation (Rain or Snow)
If dry weather is what you’re after, the months with the lowest chance of significant precipitation in Fairfax are January, December, and then November. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around early January. For example, on the week of January 1st there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in late May to early June with an average of 2 days of significant precipitation the week of May 28th.
When can you find snow in Fairfax? Weather stations report no annual snow. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.
Chance of Precipitation
The graph below shows the % chance of rainy and snowy days in Fairfax.
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Snow on the Ground
The graph below shows the average snow on the ground in Fairfax (in).
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Average Rain and Snow by Month
Show Inches
| Month | Daily Chance of Rain | Average Snow Depth (in) | Total Precipitation (in) |
|---|---|---|---|
| Jan | 1% | 0 | 0.1 |
| Feb | 2% | 0 | 0.3 |
| Mar | 4% | 0 | 0.4 |
| Apr | 10% | 0 | 1.6 |
| May | 15% | 0 | 1.8 |
| Jun | 19% | 0 | 3 |
| Jul | 10% | 0 | 1.5 |
| Aug | 12% | 0 | 2.5 |
| Sep | 9% | 0 | 1.5 |
| Oct | 9% | 0 | 1.2 |
| Nov | 2% | 0 | 0.2 |
| Dec | 2% | 0 | 0.2 |
Show Centimeters
| Month | Daily Chance of Rain | Average Snow Depth (cm) | Total Precipitation (cm) |
|---|---|---|---|
| Jan | 1 | 0 | 0.3 |
| Feb | 2 | 0 | 0.8 |
| Mar | 4 | 0 | 1 |
| Apr | 10 | 0 | 4.1 |
| May | 15 | 0 | 4.6 |
| Jun | 19 | 0 | 7.6 |
| Jul | 10 | 0 | 3.8 |
| Aug | 12 | 0 | 6.4 |
| Sep | 9 | 0 | 3.8 |
| Oct | 9 | 0 | 3 |
| Nov | 2 | 0 | 0.5 |
| Dec | 2 | 0 | 0.5 |
Humidity and Wind
Fairfax has some high humidity months, with other comfortably humid months. The least humid month is April (51.9% relative humidity), and the most humid month is December (67%).
Wind in Fairfax is usually moderate. The windiest month is April, followed by March and January. April’s average wind speed of around 10.4 knots (11.9 MPH or 19.2 KPH) is considered “a gentle breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in early April where average top sustained speeds reach 19.9 knots, which is considered a fresh breeze.
Relative Humidity (%)
The graph below shows the average % humidity by month in Fairfax.
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Wind
The graph below shows wind speed (max and average) in knots.
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Average Wind Speeds
Show Wind Speeds
All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.
| Month | Avg. Wind | Avg. Wind Feel | Sustained High Wind | High Wind Feel |
| Jan | 9.7 | Gentle breeze | 18.6 | Strong breeze |
| Feb | 9.1 | Gentle breeze | 17.1 | Strong breeze |
| Mar | 9.8 | Gentle breeze | 18.5 | Strong breeze |
| Apr | 10.4 | Gentle breeze | 19.6 | Strong breeze |
| May | 9.4 | Gentle breeze | 18.5 | Strong breeze |
| Jun | 7.8 | Gentle breeze | 16.7 | Significant breeze |
| Jul | 7.1 | Gentle breeze | 15.3 | Strong breeze |
| Aug | 7.3 | Gentle breeze | 15.3 | Significant breeze |
| Sep | 8 | Gentle breeze | 16 | Strong breeze |
| Oct | 9.2 | Gentle breeze | 17.7 | Strong breeze |
| Nov | 9.1 | Gentle breeze | 17.6 | Strong breeze |
| Dec | 8.9 | Gentle breeze | 16.4 | Significant breeze |
Show Relative Humidity by Month
| Month | Avg. Relative Humidity |
|---|---|
| Jan | 60.5% |
| Feb | 62.9% |
| Mar | 56.2% |
| Apr | 51.9% |
| May | 55.5% |
| Jun | 59.2% |
| Jul | 56.9% |
| Aug | 63.2% |
| Sep | 57.3% |
| Oct | 55.3% |
| Nov | 54.9% |
| Dec | 67% |
Is it Safe to Travel to Fairfax?
Our best data indicates this area is generally safe. As of Dec 04, 2023 there are no travel advisories or warnings for the United States; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Dec 04, 2023.
The Busiest and Least Crowded Months
The busiest month for tourism in Fairfax, SD, US is July, followed by August and February. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit Fairfax in November. Those willing to visit at these times will likely find it the least expensive month.
Estimated Tourism by Month
Most Popular Months to Visit
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Overall Fairfax Travel Experience by Season
Spring (March through May)
Humidity and temperatures combine to make this season feel moderately cold. Highs range from 76.1°F (24.5°C) and 35.4°F (1.9°C) with warmer temperatures in the later months. Rain is rare with 1 to 5 days of significant precipitation per month. Spring is fairly slow for tourism, which makes it a good time for those looking for deals.
Summer (June through August)
The middle-year months have very comfortable weather with high temperatures that are quite warm. These months see the most precipitation with 3 to 6 days of precipitation per month. June – August is the busiest season for tourism in Fairfax, so lodging and other accommodations may cost more than usual.
Fall (September through November)
Fall daily highs range from 80.4°F (26.9°C) and 44.4°F (6.9°C), which will feel chilly given the humidity and wind. It rains or snows a normal amount: 1 to 3 days per month. Tourism is the slowest during these months due to the weather, so hotels may be affordably priced.
Winter (December through February)
Weather is far too cold this time of year in Fairfax to be enjoyable for warm weather travelers. The average high during this season is between 40.4°F (4.7°C) and 31.8°F (-0.1°C). On average, it rains or snows a very small amount: 0 to 1 times per month. These times of year are the second busiest with tourists.
Best Times to Travel› the United States › Fairfax, SD, US