Climate and monthly weather forecast
Twin Falls, ID

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The high water of the Shoshone Falls in Twin Falls, Idaho, falling over the high rock cliffs and flowing into a river below
The high water of the Shoshone Falls in Twin Falls, Idaho, falling over the high rock cliffs and flowing into a river below

The climate of Twin Falls

Settled encompassed by the rugged beauty of South-central Idaho, Twin Falls is labeled under the Köppen climate classification as BSk, known as a mid-latitude steppe climate. This climate type characterizes regions with cold, sometimes harsh winters but warm to hot humid summers.

Precipitation patterns in Twin Falls exhibit consistency throughout the year, resulting in a relatively dry climate. Annual rainfall ranges from a minimum of 0.24" (6mm) in the summer months to a maximum of 1.3" (33mm) in December. Despite the variations in the amount of moisture, rainfall days remain fairly constant, only reaching a low of 4.4 days in August and peaking at 12.1 days in March.

Temperature fluctuations are prominent, the coldest month being December with a low averaging 23°F (-5°C) and a high peaking at 34°F (1.1°C). On the opposite end of the spectrum, July enjoys the highest temperature, with an average high of 89.6°F (32°C) and an average low at 62.1°F (16.7°C). Humidity levels vary inversely with the temperature, standing high in winter with December having 77% and lowering in summer, bottoming at 28% in July.

Noteworthy, the hours of sunshine Twin falls has, evolves throughout the year. The longer daylight hours are enjoyed in June with a length of 15.3 hours, reducing to a much shorter 9.1 hours in December. Throughout most of the year, the visibility remains stable at 6 miles, unaffected by the change in seasons.

The best time to visit Twin Falls

If comfort in moderate temperatures is a sightseer's preference, Twin Falls provides this mostly between May and June or September and October. These months are characterized by daily highs that range from 57.4°F (14.1°C) in April to 78.1°F (25.6°C) in June or from 77.5°F (25.3°C) in September down to 60.4°F (15.8°C) in October. Meanwhile, lower humidity levels are recorded from 46% in May to 39% in June or from 34% in September up to 49% in October.

The worst time to visit Twin Falls

Visitors sensitive to colder temperatures should bypass Twin Falls in the winter months, from December through February. The climate during these months is rather harsh, with average lows falling between 23°F (-5°C) in December and 27.5°F (-2.5°C) in February. Other weather conditions, such as increased cloud cover and reduced daylight down to 9.5 hours in December, further contributes to a less inviting atmosphere.

Spring weather in Twin Falls

Spring in Twin Falls ushers in a warm and dry climate. From March through May, temperatures progressively increase from an average high of 49.6°F (9.8°C) to 67.1°F (19.5°C). Meanwhile, average lows vary between 34.3°F (1.3°C) in March and 45.3°F (7.4°C) in May. Rainfall is relatively low during this season; however, there is a slight rise in humidity from 62% to 46%. Daylight increases from 12 hours in March to 14.6 hours in May, encompassing longer hours of sunshine.

Summer weather in Twin Falls

Summer in Twin Falls is characterized by hot, dry days with average highs fluctuating between 78.1°F (25.6°C) in June to 89.6°F (32°C) in July. Simultaneously, the average low temperature escalates from 53.2°F (11.8°C) in June to 62.1°F (16.7°C) in August. Rainfall hits its yearly low but shall not be underestimated with values ranging from 0.24" (6mm) in July to 0.47" (12mm) in June. Humidity plummets to around 28% by July.

Autumn weather in Twin Falls

Autumn in Twin Falls is marked by a cooling trend, accompanied by increasing rainfall. Starting from September through November, high temperatures drop between 77.5 to 47.1°F (8.4°C), while the low averages range from 54.5 to 31.8°F (-0.1°C). A slow increase in humidity is also observed as autumn proceeds, along with decreasing daylight hours from 12.5 in September to 9.8 in November.

Winter weather in Twin Falls

Winter in Twin Falls typically exhibits freezing temperatures. Throughout December to February, high temperatures plummet from 34°F (1.1°C) to 39.7°F (4.3°C), while lows fall between 23°F (-5°C) and 27.5°F (-2.5°C). Rainfall increases during this period, with 1.3" (33mm) expected in December. In addition to this, it is the season when Twin Falls sees snowfall, ranging from 5.04" (128mm) in December down to 3.62" (92mm) in February.

Weather in January

January in Twin Falls, Idaho, begins the year with chilly weather conditions. A layer of snow covers the landscape with 5.04" (128mm) of snowfall on average; a significant decrease in temperature marks the start of winter. Compared to December, the cold is more pronounced with the temperature hitting a high of only 34.9°F (1.6°C) and a low of 24.1°F (-4.4°C). Weather in January »

Weather in February

With the arrival of February, Twin Falls witnesses a mild increase in temperature. The cold weather persists, but it drops slightly less snow with an average of 3.62" (92mm). March's promise of spring is still a distant hope, as residents continue to brave the frosty temperatures and chilly winds. Weather in February »

Weather in March

March sees an early glimpse of spring in Twin Falls. The city starts to thaw from winter's hard freeze with a rise in temperature, while the accompanying snowfall significantly drops to 1.5" (38mm). The transition from the biting cold to warmer days starts to take place. Weather in March »

Weather in April

In April, the weather in Twin Falls becomes more pleasant. The city embraces the full onset of spring with temperatures climbing to a comfortable 57.4°F (14.1°C) high and the snowfall finally ceases, signaling winter's departure. Weather in April »

Weather in May

May is a cheerful month in Twin Falls, with temperatures reaching a comfortable 67.1°F (19.5°C) high. Rainfall during this month is relatively low, with an average of 0.75" (19mm) signifying the full arrival of dry and warm weather. Weather in May »

Weather in June

June marks the onset of summer in Twin Falls, with temperatures spiking to a warm 78.1°F (25.6°C) high. Compared to May, June witnesses a significant increase in warm weather, and rainfall decreases to just 0.47" (12mm). Activities move to the town's water bodies as locals start indulging in rowing, fishing, and watersports. Weather in June »

Weather in July

July is the warmest month in Twin Falls, with temperatures peaking to a scorching high of 89.6°F (32°C). Rainfall is at its lowest for the year, with a mere 0.24" (6mm), and the city is embraced in a dry, hot summer. The extreme heat pushes locals towards indoor activities or encourages them to seek solace in nearby waterbodies or shaded areas. Weather in July »

Weather in August

In August, Twin Falls experiences a subtly milder version of July's sweltering weather. Compared to July, the temperature takes a slight dip, but August remains significantly hot with an 88°F (31.1°C) high. The scorching summer weather continues, but relief is in sight as the month concludes. Weather in August »

Weather in September

September brings with it the first hints of fall in Twin Falls. As compared to August, the temperature settles to a comforting 77.5°F (25.3°C) high, and the foliage begins to change color. The stark summer heat begins to diminish, and locals start experiencing cooler breezes. Weather in September »

Weather in October

October in Twin Falls is a celebration of autumn. Compared to September, temperatures further drop, and the city is enveloped in the vibrant hues of fall. Be it the crisp air, the crackling of fallen leaves or the smell of hot apple cider, October has a unique charm about it. Weather in October »

Weather in November

November ushers in winter in Twin Falls with a noticeable drop in temperatures. While the crisp fall weather is still evident, the chill of winter grows in the breeze, preparing everyone for the coming cold season. The first snowflakes start making an appearance with nearly 1.69" (43mm) of average snowfall. Weather in November »

Weather in December

December marks the peak of winter in Twin Falls, with severe cold and the heaviest snowfall of 4.53" (115mm). The city becomes a quiet, snow-dusted landscape as people retreat indoors to celebrate the holiday season. Compared to November, the chilly conditions intensify making way for the coldest month of the year. Weather in December »
Updated: Jun 19, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the most humid month?

The most humid month is January, with an average relative humidity of 78%.

How many days does it rain?

Throughout the year, there are 91.4 rainfall days, and 9.29" (236mm) of precipitation is accumulated.

When does it snow?

January through April, October through December are months with snowfall.

What is the snowiest month?

January is the month with the most snowfall. Snow falls for 8.9 days and accumulates 5.04" (128mm) of snow.

How many days does it snow in Twin Falls?

In Twin Falls, during the entire year, snow falls for 35.5 days and aggregates up to 17.32" (440mm) of snow.

When is the lowest UV index?

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Twin Falls, and the time zone changes from MST to MDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from MDT to MST.

When it does not snow?

May through September are months without snowfall.

When are the longest days?

The month with the longest days is June, with an average of 15h and 18min of daylight.

What month is the hottest?

The month of July, characterized by an average high of 89.6°F (32°C) and a low of 62.1°F (16.7°C), is recognized as the warmest.

What is the least humid month?

With an average relative humidity of 28%, July is the least humid month.

What is the driest month?

July and August are months with the least rain when the rain falls for 4.5 days and typically aggregates up to 0.24" (6mm) of rain.

What month has the most sunshine in Twin Falls?

The month with the most sunshine is July, with an average of 12h of sunshine.

When is the highest UV index?

The month with the highest UV index is July, with an average maximum UV index of 7.

What month is the coldest?

During the coldest month in Twin Falls, December, temperatures average a high of 34°F (1.1°C) and a low of 23°F (-5°C).

What is the rainiest month?

The month with the most rainfall is December, when the rain falls for 7.5 days and typically aggregates up to 1.3" (33mm) of precipitation.

What is the month with the shortest days?

With an average of 9h and 6min of daylight, December has the shortest days of the year.

What is the month with the least sunshine?

With an average of 5.8h of sunshine, December has the least sunshine of the year.

Average temperature
Twin Falls, ID

Average temperature - Twin Falls, ID

The warmest month (with the highest average high temperature) is July (89.6°F).
The month with the lowest average high temperature is December (34°F).

The month with the highest average low temperature is July (62.1°F).
The coldest month (with the lowest average low temperature) is December (23°F).

Average pressure
Twin Falls, ID

Average pressure - Twin Falls, ID

The month with the highest atmospheric pressure is January (30.28"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).

Average wind speed
Twin Falls, ID

Average wind speed - Twin Falls, ID

The windiest month (with the highest average wind speed) is April (10mph).
The calmest month (with the lowest average wind speed) is August (7.3mph).

Average humidity
Twin Falls, ID

Average humidity - Twin Falls, ID

The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is July (28%).

Average rainfall
Twin Falls, ID

Average rainfall - Twin Falls, ID

The wettest month (with the highest rainfall) is December (1.3").
The driest months (with the least rainfall) are July and August (0.24").

Average rainfall days
Twin Falls, ID

Average rainfall days - Twin Falls, ID

The month with the highest number of rainy days is March (12.1 days).
The month with the least rainy days is August (4.4 days).

Average snowfall
Twin Falls, ID

Average snowfall - Twin Falls, ID

The month with the highest snowfall is January (5.04").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days
Twin Falls, ID

Average snowfall days - Twin Falls, ID

The month with the highest number of snowfall days is December (9.4 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight / Average sunshine
Twin Falls, ID

Average daylight / Average sunshine - Twin Falls, ID

The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).

The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).

Average sunshine days
Twin Falls, ID

Average sunshine days - Twin Falls, ID

The month with the most sunshine days is August (23.3 days).
The month with the least sunshine days is March (14.7 days).

Average UV index
Twin Falls, ID

Average UV index - Twin Falls, ID

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average visibility
Twin Falls, ID

Average visibility - Twin Falls, ID

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Twin Falls, Idaho, USA

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