Climate and monthly weather forecastHelena, MT
Climate and monthly weather forecast
The climate of Helena
Helena, Montana, USA, is a location renowned for its Dfb - Humid continental climate. According to the Köppen climate classification, this climate is characterized by no dry season, and warm summers. Based on location's annual weather records, a mix of moderate to transitional weather conditions are experienced throughout the year.A study of the climate information of Helena displays seasonal variations in all weather parameters. A distinct progression can be observed in temperature from the cold months to the warm months. During January, temperatures have been historically low with temperatures hovering around 16°F (-8.9°C) in the low range and 30.4°F (-0.9°C) in the upper band. By July, the temperatures peak with highs and lows ranging from 50.4°F (10.2°C) to 80.2°F (26.8°C) respectively.
Humidity is another noteworthy parameter to consider. January and February witness relatively high humidity levels reaching up to 85% and 83% respectively. A decreasing trend is noticed that hits a low in July with 46% before climbing back again towards the end of the year.
Notably, rainfall and snowfall display a particular pattern. While Helena receives appreciable amounts of rainfall throughout the year with a maximum of 2.01" (51mm) in June, months from January to April are known for significant snowfall. Snowfall begins to decline in April, almost ceasing by the onset of May.
The best time to visit Helena
With a keen look at the prevailing annual weather conditions, the period between May and August stands out as the most suitable time to visit Helena. During this time, temperatures range from 36.9°F (2.7°C) to 80.2°F (26.8°C), providing the warmth desired by many tourists. These months provide 15 hours of daylight on average, with peak sunshine hours in June, amounting to 11.1 hours. The UV index is at its optimum from June to July with a value of 6. Additionally, rain is consistent but not overly excessive, ensuring green and vibrant landscapes without causing major disruptions to outdoor activities.The worst time to visit Helena
If one is averse to colder conditions, the period from November to February might be less desirable. During these months, temperatures can plunge as low as 14.2°F (-9.9°C). Snowfall is considerable during this period, with up to 6.18" (157mm) recorded in February. Furthermore, the length of the day can be as short as 8.6 hours in December, leading to shorter daylight hours for exploration and activities.Spring weather in Helena
The months of March, April and May bring about the spring season in Helena. Temperatures during this period range from 23.2°F (-4.9°C) to 59.4°F (15.2°C) with increasing daylight hours from 12 hours in March to 15 hours in May. Rainfall increases steadily from 1.1" (28mm) in March to 1.5" (38mm) in May.Summer weather in Helena
During the summer months of June, July, and August, temperatures escalate, ranging from 44.2°F (6.8°C) to 80.2°F (26.8°C). A noticeable increase in daylight hours occurs, peaking at 15.8 hours in June. Rainfall is rather regular, with a maximum of 2.01" (51mm) in June.Autumn weather in Helena
In the autumn months of September, October, and November, Helena witnesses a gradual decrease in temperature from 43.9°F (6.6°C) to 22.1°F (-5.5°C). Length of daylight decreases from 12.5 hours in September to 9.4 hours in November. Rainfall hovers around 0.83" (21mm) monthly, contributing to the picturesque fall landscapes.Winter weather in Helena
From December to February, Helena succumbs to winter’s chill. With temperatures ranging from a low of 14.2°F (-9.9°C) to a high of 30.4°F (-0.9°C), these months are characterized by a quiet, snowy beauty. Snowfall ranges from 4.41" (112mm) in December to 6.18" (157mm) in February. The days are shorter with December having the shortest day length of 8.6 hours.Weather in January
January in Helena, Montana is dominated by cold, snowy conditions. This is evidenced by an average minimum temperature of 16°F (-8.9°C) and an average maximum of 30.4°F (-0.9°C). This month also sees high levels of snowfall, making it a winter wonderland. Weather in January »Weather in February
Similar to January, February continues to experience cold and snowy weather. The dipping temperature, from 30.4°F (-0.9°C) in January to 29.7°F (-1.3°C), signifies the nippy nature of this month. In addition, Helena sees an increase in snowfall with an average of 6.18" (157mm). Weather in February »Weather in March
The weather in Helena, Montana undergoes a noticeable change in March. The city witnesses a significant rise in maximum temperature from 29.7°F (-1.3°C) in February to 39.7°F (4.3°C). Consequently, snowfall decreases and is replaced with rainfall, marking the beginning of the spring season. Weather in March »Weather in April
By the time April rolls around, winter's grip on Helena is loosened. The relatively warmer temperatures of April, peaking at 47.8°F (8.8°C), mark the complete arrival of spring. The increased sunlight and decreasing frequency of snowfall allows for wildlife to emerge and vegetation to flourish. Weather in April »Weather in May
Helena experiences a stronger sun in May, with temperatures scaling up to an average high of 59.4°F (15.2°C). The weather transitions rapidly from the residual chill of spring to the early hints of summer. The snowfall ceases entirely this month, giving way to sunnier days and conducive weather for outdoor exploration. Weather in May »Weather in June
June ushers in the first full month of summer in Helena, Montana, with the average temperatures hovering around a comfortable 69.4°F (20.8°C). The onset of summer is also accompanied by the longest daylight hours of the year. The increased daylight enables more time for outdoor adventures such as hiking, fishing, or camping in Helena's picturesque landscapes. Weather in June »Weather in July
The warm trend continues into July, with the weather hitting the peak of summer. This month experiences the highest average temperature for the year, reaching up to 80.2°F (26.8°C). Celebrations of summer are in full swing, with locals and tourists indulging in a multitude of outdoor recreational activities. Weather in July »Weather in August
August in Helena maintains the summer heat, albeit with a slight dip in temperature from July's peak. With an average high of 78.1°F (25.6°C), the weather remains intertwined with warmth and long daylight hours. August is also distinguished by a low average rainfall of 0.87" (22mm). Weather in August »Weather in September
September witnesses the onset of fall in Helena, Montana. The weather begins a gradual cooling with temperatures averaging around 68.2°F (20.1°C). This month marks the transition from the height of summer to the beginnings of autumn. Weather in September »Weather in October
October in Helena ushers in a pronounced shift towards cooler weather, with an average high temperature settling at 51.3°F (10.7°C). The vibrant colors of fall foliage are on full display, painting the city in shades of gold and rust. Weather in October »Weather in November
November in Helena marks the start of the winter season. The average high temperature further plummets to a crisp 37.4°F (3°C). Snowfall resumes this month, adorning the city with its winter coat. As the wintry chill takes hold, outdoor activities transition to winter sports such as skiing or ice fishing. Weather in November »Weather in December
December is known for its biting cold in Helena, Montana, with the minimum temperature dropping to 14.2°F (-9.9°C). This sets the stage for a white Christmas as the city becomes a winter wonderland, blanketed in snow. Despite the cold, the festive spirit is elevated, bringing a unique charm to Helena. Weather in December »Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
With an average relative humidity of 85%, January is the most humid month in Helena.
The months with the least rainfall are January and December Rain falls for 8.4 days and accumulates 0.63" (16mm) of rain.
In Helena, Montana, during the entire year, the rain falls for 123.7 days and collects up to 12.4" (315mm) of precipitation.
January through May, September through December are months with snowfall in Helena.
Throughout the year, there are 80.4 snowfall days, and 34.88" (886mm) of snow is accumulated.
The month with the least sunshine in Helena is January, with an average of 5.6h of sunshine.
The month with the most snowfall is February, when snow falls for 16.2 days and typically aggregates up to 6.18" (157mm) of snow.
The month with the lowest UV index is February, with an average maximum UV index of 1.
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.
June is the month with the most rainfall in Helena, Montana. Rain falls for 13.3 days and accumulates 2.01" (51mm) of precipitation.
June through August are months without snowfall in Helena.
With an average of 15h and 48min of daylight, June has the longest days of the year.
In Helena, July records the average highest temperatures, peaking at 80.2°F (26.8°C) and reaching a low of 50.4°F (10.2°C).
The months with the lowest humidity in Helena are July and August, with an average relative humidity of 46%.
The month with the most sunshine is July, with an average of 11.7h of sunshine.
With an average maximum UV index of 6, July is the month with the highest UV index in Helena, Montana.
December brings the lowest temperatures, with an average high of 27.7°F (-2.4°C) and an average low of 14.2°F (-9.9°C).
With an average of 8h and 36min of daylight, December has the shortest days of the year in Helena, Montana.
Average temperature
Helena, MT
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is December (27.7°F).
The month with the highest average low temperature is July (50.4°F).
The coldest month (with the lowest average low temperature) is December (14.2°F).
Average pressure
Helena, MT
- Average pressure in January:
30.18"Hg - Average pressure in February:
30.13"Hg - Average pressure in March:
30.03"Hg - Average pressure in April:
29.97"Hg - Average pressure in May:
29.95"Hg - Average pressure in June:
29.9"Hg
- Average pressure in July:
29.95"Hg - Average pressure in August:
29.95"Hg - Average pressure in September:
29.98"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.11"Hg - Average pressure in December:
30.17"Hg
The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed
Helena, MT
- Average wind speed in January:
7mph - Average wind speed in February:
6.5mph - Average wind speed in March:
6.6mph - Average wind speed in April:
6.9mph - Average wind speed in May:
5.8mph - Average wind speed in June:
6mph
- Average wind speed in July:
5.2mph - Average wind speed in August:
5mph - Average wind speed in September:
5.9mph - Average wind speed in October:
6.7mph - Average wind speed in November:
7.1mph - Average wind speed in December:
6.8mph
The windiest month (with the highest average wind speed) is November (7.1mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity
Helena, MT
The month with the highest relative humidity is January (85%).
The months with the lowest relative humidity are July and August (46%).
Average rainfall
Helena, MT
- Average rainfall in January:
0.63" - Average rainfall in February:
0.87" - Average rainfall in March:
1.1" - Average rainfall in April:
1.5" - Average rainfall in May:
1.5" - Average rainfall in June:
2.01"
- Average rainfall in July:
0.83" - Average rainfall in August:
0.87" - Average rainfall in September:
0.94" - Average rainfall in October:
0.83" - Average rainfall in November:
0.71" - Average rainfall in December:
0.63"
The wettest month (with the highest rainfall) is June (2.01").
The driest months (with the least rainfall) are January and December (0.63").
Average rainfall days
Helena, MT
- Average rainfall days in January:
8.4 days - Average rainfall days in February:
7.4 days - Average rainfall days in March:
12.8 days - Average rainfall days in April:
15.1 days - Average rainfall days in May:
15.8 days - Average rainfall days in June:
13.3 days
- Average rainfall days in July:
8.8 days - Average rainfall days in August:
9.1 days - Average rainfall days in September:
8.1 days - Average rainfall days in October:
10 days - Average rainfall days in November:
7 days - Average rainfall days in December:
7.9 days
The month with the highest number of rainy days is May (15.8 days).
The month with the least rainy days is November (7 days).
Average snowfall
Helena, MT
- Average snowfall in January:
4.41" - Average snowfall in February:
6.18" - Average snowfall in March:
5.12" - Average snowfall in April:
5.12" - Average snowfall in May:
0.67" - Average snowfall in June:
0"
The month with the highest snowfall is February (6.18").
The months with the least snowfall are June, July and August (0").
Average snowfall days
Helena, MT
- Average snowfall days in January:
13.3 days - Average snowfall days in February:
16.2 days - Average snowfall days in March:
11.7 days - Average snowfall days in April:
8.8 days - Average snowfall days in May:
1.3 days - Average snowfall days in June:
0.2 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0.7 days - Average snowfall days in October:
4.6 days - Average snowfall days in November:
9.5 days - Average snowfall days in December:
14.1 days
The month with the highest number of snowfall days is February (16.2 days).
The months with the least snowfall days are July and August (0 days).
Average daylight / Average sunshine
Helena, MT
- Average daylight in January:
9h and 6min - Average daylight in February:
10h and 24min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 36min - Average daylight in May:
15h and 0min - Average daylight in June:
15h and 48min
- Average daylight in July:
15h and 24min - Average daylight in August:
14h and 6min - Average daylight in September:
12h and 30min - Average daylight in October:
10h and 54min - Average daylight in November:
9h and 24min - Average daylight in December:
8h and 36min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in January:
5h and 36min - Average sunshine in February:
6h and 0min - Average sunshine in March:
7h and 48min - Average sunshine in April:
9h and 6min - Average sunshine in May:
10h and 18min - Average sunshine in June:
11h and 6min
- Average sunshine in July:
11h and 42min - Average sunshine in August:
11h and 30min - Average sunshine in September:
9h and 42min - Average sunshine in October:
7h and 0min - Average sunshine in November:
6h and 12min - Average sunshine in December:
5h and 48min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is January (Average sunshine: 5h and 36min).
Average sunshine days
Helena, MT
- Average sunshine days in January:
15.2 days - Average sunshine days in February:
10.4 days - Average sunshine days in March:
11 days - Average sunshine days in April:
9.8 days - Average sunshine days in May:
12.2 days - Average sunshine days in June:
14.2 days
- Average sunshine days in July:
20.5 days - Average sunshine days in August:
19.5 days - Average sunshine days in September:
19.3 days - Average sunshine days in October:
17.2 days - Average sunshine days in November:
16.1 days - Average sunshine days in December:
15.5 days
The month with the most sunshine days is July (20.5 days).
The month with the least sunshine days is April (9.8 days).
Average UV index
Helena, MT
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover
Helena, MT
The month with the most cloud cover is February (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 15).
Average visibility
Helena, MT
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).
