Climate and monthly weather forecast
Grand Junction, CO

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The scenic Grand Junction in Colorado with the iconic Colorado River and high hills nearby
The scenic Grand Junction in Colorado with the iconic Colorado River and high hills nearby

The climate of Grand Junction

Grand Junction, located in the mid-latitude steppe region, adheres mostly to the BSk predominate climate according to Köppen climate classification. These circumstances provide a semi-arid climate with hot summers and cold winters. The temperature varies significantly throughout the year, with highs reaching 86.9°F (30.5°C) in July and dipping as low as 18.3°F (-7.6°C) in January.

The town experiences a broad range of humidity levels, peaking at 78% in January and decreasing to 29% by June. Rainfall is a common phenomenon, sprinkling the town with a minimum of 0.51" (13mm) in June to a maximum of 1.06" (27mm) in March. Nonetheless, there are less rainy days in November, only 5.5 days, compared with 10.4 days in March.

Snowfall is predominantly accentuated in the winter months, from December to February, with January encountering the most significant snowfall of 3.74" (95mm). Cloud cover varies moderately, with December displaying the highest percentage at 31%, and June showing the lowest at 11%. The pressure also shows a slight fluctuation throughout the year, maintaining between 29.9" (759mm) in May and 30.27" (769mm) in January.

The best time to visit Grand Junction

June emerges as the prime month to explore Grand Junction, affirmed by the appropriate weather conditions. The temperature reaches a high of 82.2°F (27.9°C), providing an ideal environment for outdoor activities. Furthermore, the humidity drops substantially to 29%, manifesting a comfortable atmosphere. The area also receives a minimum rainfall of only 0.51" (13mm) and experiences a limited number of rainy days, merely 5.6 days.

The worst time to visit Grand Junction

Touring Grand Junction in the winter months might not be a delightful experience for everyone. Particularly in January, where the temperature hits rock bottom at 18.3°F (-7.6°C). The high amount of snowfall, an ample 3.74" (95mm), also contributes to the adverse conditions for travelling. Furthermore, in this period, the high humidity, peaking at 78%, may result in quite discomforting conditions.

Spring weather in Grand Junction

Spring in Grand Junction, from March to May, signifies warming temperatures, with highs ranging from 50.7°F (10.4°C) to 69.1°F (20.6°C). Rainfall in this season moderately varies from 1.06" (27mm) in March to 0.55" (14mm) in May. March sees an elevated number of rainy days with 10.4, which gradually recedes to 7.7 in May. The humidity also follows a descending trend, starting at 55% in March and dropping to 37% in May

Summer weather in Grand Junction

With summer extending from June to August, Grand Junction's average high temperatures escalate from a pleasant 82.2°F (27.9°C) in June to a warm 86.9°F (30.5°C) in July, before tapering off slightly to 84.2°F (29°C) in August. Even though June sees the least rainfall of 0.51" (13mm) of the year, by August, it increases to 0.75" (19mm). However, the number of rainy days remains quite similar, oscillating around 8.7 days in July and August.

Autumn weather in Grand Junction

Autumn in Grand Junction brings an appreciable coolness, with temperatures retreating from 76.5°F (24.7°C) in September to a mild 49.1°F (9.5°C) in November. Precipitation and the number of rainy days coincide at 0.63" (16mm) and 7.3 days in September, then slight increases to 0.94" (24mm) and 7.4 days in October. November sees the least number of rainy days at 5.5 days though receives 0.55" (14mm) of rain.

Winter weather in Grand Junction

Winter spans from December until February and most notably, features temperatures fluctuating between 18.3°F (-7.6°C) and 39.6°F (4.2°C). Heavier snowfall becomes apparent in this period, peaking at 3.74" (95mm) in January. The waning daylight hours contribute to the cold weather, with the shortest span of 9.5 hours occurring in December and gradually increasing to 10.8 hours by February.

Weather in January

January in Grand Junction, Colorado sees a mingling of chilly temperatures and moderate humidity. The city experiences the year's coldest temperatures with highest around 34.9°F (1.6°C) and lowest around 18.3°F (-7.6°C). An overall sense of freshness pervades as snowfalls are not uncommon, adding to the overall humidity. Weather in January »

Weather in February

Transitioning into February, Grand Junction witnesses a gradual climb in temperatures. Compared to January, both maximum and minimum temperatures rise, reaching up to 39.6°F (4.2°C) and 23.5°F (-4.7°C) respectively. The relative humidity decreases, the city experiencing less snowfall than in January, although winter conditions persist. Weather in February »

Weather in March

By March, Grand Junction begins to shed the harsh winter temperatures. The weather is notably warmer compared to February, with a significant leap in highest temperatures up to 50.7°F (10.4°C). Sunshine hours rise, adding to the perception of warming days as winter fades away. Weather in March »

Weather in April

April sees a resurgence of pleasant conditions in Grand Junction. An increase in temperature is notable, with highs soaring to 58.6°F (14.8°C). The transition from winter to spring is complete, with snowfall becoming highly unlikely. Weather in April »

Weather in May

May in Grand Junction marks the onset of summer. Warmer temperatures prevail, resulting in a distinct shift from Spring, with highs nearly reaching 70.1°F (21.2°C). Days continue to grow longer, and with the least amount of annual rain, outdoor activities become very popular. Weather in May »

Weather in June

June in Grand Junction greets the summer solstice with temperatures nearing 82.2°F (27.9°C). As the hottest month of the year, precautions against heat-related conditions are warranted. Enduring the longest daylight hours, the city bathes in an abundant 14.9 hours of light. Weather in June »

Weather in July

Taking over from June, July continues the summer spell with maximum temperatures averaging around 86.9°F (30.5°C). Despite possessing the highest average temperatures, it does not experience as much sunshine as the previous month. Weather in July »

Weather in August

August is a month of mild changes for Grand Junction. The weather accommodates a mild decrease in highest temperature to 84.2°F (29°C), still providing ample warmth. The humidity remains low despite being peak summer month, with rain in moderation. Weather in August »

Weather in September

In September, Grand Junction ushers in the first hints of autumn as temperatures start to decrease. Weather conditions take a gentle turn from the peak summer heat, with temperatures dropping to a pleasant 76.5°F (24.7°C) at most. Weather in September »

Weather in October

October in Grand Junction signifies the arrival of quintessential fall weather. A sharp decline in temperatures sees a lower limit of 40.5°F (4.7°C), signaling the beginning of cooler days and even colder nights. Diverse weather patterns emerge as the occasional snowfall enriches the fall foliage. Weather in October »

Weather in November

November in Grand Junction is marked by a transition to winter-like conditions. With a decrease in highest temperature to as low as 49.1°F (9.5°C), crispness permeates the air. Snowfall occurrences increase and while they may not be frequent, they do contribute to the overall moisture. Weather in November »

Weather in December

December introduces winter in full swing, as temperatures continue to drop with a decrease to 36.3°F (2.4°C) at most. Grand Junction experiences the most snowfall during this month, ensuring a white Christmas. The city also sees the shortest daylight hours, plunging it into longer nights. Weather in December »
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Frequently asked questions

What month is the coldest in Grand Junction?

In Grand Junction, January is the coldest month, with temperatures averaging a high of 34.9°F (1.6°C) and a low of 18.3°F (-7.6°C).

What is the most humid month in Grand Junction?

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

How much does it rain in Grand Junction?

Throughout the year, in Grand Junction, there are 93.6 rainfall days, and 8.46" (215mm) of precipitation is accumulated.

When does it snow in Grand Junction?

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

How much does it snow in Grand Junction?

In Grand Junction, Colorado, during the entire year, snow falls for 28.3 days and aggregates up to 11.5" (292mm) of snow.

What is the month with the least sunshine in Grand Junction?

January has the least sunshine of the year, with an average of 6.3h of sunshine.

When is the lowest UV index in Grand Junction?

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

What is the rainiest month in Grand Junction?

The month with the most rainfall is March, when the rain falls for 10.4 days and typically aggregates up to 1.06" (27mm) of precipitation.

When is Daylight Saving Time (DST) in Grand Junction?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, 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 in Grand Junction?

May through September are months without snowfall in Grand Junction.

What is the least humid month in Grand Junction?

With an average relative humidity of 29%, June is the least humid month.

What is the driest month in Grand Junction?

The month with the least rainfall is June, when the rain falls for 5.6 days and typically collects 0.51" (13mm) of precipitation.

When are the longest days in Grand Junction?

The month with the longest days in Grand Junction, Colorado, is June, with an average of 14h and 54min of daylight.

What month has the most sunshine in Grand Junction?

With an average of 12h of sunshine, June has the most sunshine of the year.

What are the months with the highest UV index in Grand Junction?

June through August, with an average maximum UV index of 6, are months with the highest UV index.

What part of the year is the hottest in Grand Junction?

Grand Junction's warmest weather arrives in July, when temperatures average a high of 86.9°F (30.5°C) and a low of 60.4°F (15.8°C).

When does it snow the most in Grand Junction?

The month with the most snowfall in Grand Junction is December, when snow falls for 6.9 days and typically aggregates up to 3.74" (95mm) of snow.

What is the month with the shortest days in Grand Junction?

December has the shortest days of the year, with an average of 9h and 30min of daylight.

Average temperature
Grand Junction, CO

Average temperature - Grand Junction, CO

The warmest month (with the highest average high temperature) is July (86.9°F).
The month with the lowest average high temperature is January (34.9°F).

The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (18.3°F).

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Average pressure
Grand Junction, CO

Average pressure - Grand Junction, CO

The month with the highest atmospheric pressure is January (30.27"Hg).
The months with the lowest atmospheric pressure are May and June (29.9"Hg).

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Average wind speed
Grand Junction, CO

Average wind speed - Grand Junction, CO

The windiest month (with the highest average wind speed) is June (7.5mph).
The calmest month (with the lowest average wind speed) is January (4.2mph).

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Average humidity
Grand Junction, CO

Average humidity - Grand Junction, CO

The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is June (29%).

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Average rainfall
Grand Junction, CO

Average rainfall - Grand Junction, CO

The wettest month (with the highest rainfall) is March (1.06").
The driest month (with the least rainfall) is June (0.51").

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Average rainfall days
Grand Junction, CO

Average rainfall days - Grand Junction, CO

The month with the highest number of rainy days is March (10.4 days).
The month with the least rainy days is November (5.5 days).

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Average snowfall
Grand Junction, CO

Average snowfall - Grand Junction, CO

The month with the highest snowfall is December (3.74").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days
Grand Junction, CO

Average snowfall days - Grand Junction, CO

The month with the highest number of snowfall days is January (7.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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Average daylight / Average sunshine
Grand Junction, CO

Average daylight / Average sunshine - Grand Junction, CO

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

The month with the most sunshine is June (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 6h and 18min).

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Average sunshine days
Grand Junction, CO

Average sunshine days - Grand Junction, CO

The month with the most sunshine days is November (22.3 days).
The month with the least sunshine days is February (15.8 days).

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Average UV index
Grand Junction, CO

Average UV index - Grand Junction, CO

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

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Average visibility
Grand Junction, CO

Average visibility - Grand Junction, CO

The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).

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Grand Junction, Colorado, USA

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