Climate and monthly weather forecastRoundup, MT
Climate and monthly weather forecast
The climate of Roundup
Belonging to the Mid-latitude steppe, according to the Köppen climate classification, Roundup, Montana, USA experiences a BSk climate. Nestled in a geographical setting that lends itself to a semiarid climate, Roundup undergoes an array of weather conditions throughout the year.Examining the climate data readily reveals patterns and significant variations. Boasting an extensive temperature range, high temperatures fluctuate from a crisp 31.1°F (-0.5°C) in December to a sultry 84.7°F (29.3°C) in July. The town's low temperatures follow a similar trajectory, plunging to 18.5°F (-7.5°C) in January and December, then ascending to 62.4°F (16.9°C) come July.
Roundup receives an annual rainfall between 0.55" (14mm) in January and 1.97" (50mm) in May. The number of rainfall days too sees considerable variation spanning from 4.6 days in February to 15.6 days in May. A striking characteristic of Roundup's weather is its changeable snowfall, registering 3.15" (80mm) in January, dropping off to zero from June to August, before picking up again in winter.
Relative humidity shows a decrease from a peak of 77% in January to a low of 39% by August. The level of cloud cover throughout the year is typically moderate. Notably, Roundup enjoys substantial daylight, peaking at 15.8 hours in June, the longest in the year.
The Best Time to Visit Roundup
When thinking about visiting Roundup, it's crucial to keep in mind that weather conditions vary significantly throughout the year. Generally, the most favorable time to visit is during the late spring to early fall when the weather is most comfortable. The temperatures during this time range from a pleasant 64.2°F (17.9°C) in May to a warm 82.8°F (28.2°C) in August. Rainfall is moderate, while the sunshine hours peak, reaching 15.8 hours in June.The Worst Time to Visit Roundup
Conversely, January represent the most challenging period to visit Roundup due mainly to harsh winter conditions. Both high and low temperatures are at a year's low, registering 31.8°F (-0.1°C) and 18.5°F (-7.5°C) respectively. Coupled with high snowfall of 3.15" (80mm) and limited sunshine hours, this period may not be particularly appealing to visitors.Spring Weather in Roundup
Spring weather in Roundup marks a shift from the frigid winters to warmer conditions. High temperatures rise from a cool 45°F (7.2°C) in March to a comfortable 64.2°F (17.9°C) by May. The equivalent low temperatures make a similar ascension from 29.3°F (-1.5°C) to 45.7°F (7.6°C). A notable feature of spring in Roundup is the increase in rainfall, peaking at 1.97" (50mm) in May.Summer Weather in Roundup
Summer in Roundup brings with it a warm and pleasant weather pattern. The high temperatures rise consistently from June to July, with peaks around 84.7°F (29.3°C), while the lows sit comfortably between 54.5°F (12.5°C) and 62.4°F (16.9°C). Notably, summers are the driest season, with the lowest rainfall of 0.83" (21mm) and the least number of rainy days in July.Autumn Weather in Roundup
Autumn heralds a gradual decrease in temperature, with highs moving from a warm 72.7°F (22.6°C) in September down to a crisp 43.2°F (6.2°C) by November. Similarly, the low temperatures also decline from 53.2°F (11.8°C) to a colder 28.8°F (-1.8°C). During this phase, rainfall stays relatively steady at around 0.8" (20mm), and there are fewer rainy days compared to spring and summer.Winter Weather in Roundup
Characterized by cold temperatures and substantial snowfall, winters in Roundup are quite severe. High temperatures range from 56.3°F (13.5°C) in December to 31.8°F (-0.1°C) in January. Concurrently, the low temperatures plunge to 18.5°F (-7.5°C) in January and December. Notably, snowfall exceeds 2" (51mm) in December and January, making this a challenging period for outdoor activities.Weather in January
The city of Roundup, Montana, USA finds itself in the grip of winter during January. The weather is defined by chilly temperatures, with lows reaching 18.5°F (-7.5°C) and highs just over 31.8°F (-0.1°C). Snowfall is quite prevalent this month, marking the landscape in shades of pristine white. Weather in January »Weather in February
February sees a slight uptick in the temperature in Roundup, Montana, USA, though the cold winter still holds sway. The month also boasts a distinctive trait of slightly higher snowfall than January, 3.78" (96mm) as compared to 3.15" (80mm), keeping the winter sports season in full swing. Weather in February »Weather in March
March indicates an advent toward spring in Roundup, Montana, with weather conditions easing out. The temperature rises notably with highs peaking around 45°F (7.2°C), offering gradual relief from the winter chill. However, snowfall continues as remnants of winter, with shorter snowfall days compared to the previous months. Weather in March »Weather in April
Roundup, Montana, USA transitions into spring in April, with the weather conditions becoming considerably milder. Temperatures continue to rise, touching up to 53.8°F (12.1°C), signaling the retreat of the winter. Rainfall increases significantly, reaching up to 1.65" (42mm), the highest so far in the year, signaling the beginning of the rainy season. Weather in April »Weather in May
May brings a significant shift in weather pattern in Roundup, Montana, USA as the city fully embraces spring. Decent temperatures are observed this month with highs hovering around 64.2°F (17.9°C), creating a refreshing and comfortable atmosphere. Weather in May »Weather in June
June ushers in the season of summer in Roundup, Montana, USA. The weather patterns now settle into a warm, comfortable routine, with temperatures reaching their peak at around 75.2°F (24°C). Though rainfall continues, the downpour decreases compared to May. Weather in June »Weather in July
July is the hottest month in Roundup, Montana, with the temperature soaring up to 84.7°F (29.3°C). Despite this peak in the temperature, rainfall decreases to its lowest at 0.83" (21mm), offering a genuinely dry and warm summer month. Weather in July »Weather in August
August in Roundup, Montana, experiences a dip in temperature as compared to July. This month mimics July with lower rainfall and similar temperature patterns, casting a warm and relatively dry weather. This decline in temperature and humidity, coupled with persistent hours of sunshine, foster perfect conditions for summer events and festivals. Weather in August »Weather in September
September signals the onset of fall in Roundup, Montana, USA, with temperatures dropping to less warm degrees. The weather is marked by a decline in rainfall and a slight increase in humidity compared to August. An interesting note for this month is a trivial presence of snowfall, merely 0.12" (3mm), perhaps an early indication of the incoming winter. Weather in September »Weather in October
October ushers in more characteristic fall weather in Roundup, Montana, while temperatures continue their downward trajectory from September. Rainfall maintains a steady trend, helping to paint the town with brilliant autumn hues. Weather in October »Weather in November
November shows a marked shift toward winter in Roundup, Montana, as temperatures dip further. Snowfall significantly increases compared to the previous month, reaching 2.2" (56mm) and paving the way for the upcoming winter. The drop in temperature corresponds with shorter days and less sunshine. Weather in November »Weather in December
December in Roundup, Montana, brings in full-fledged winter with the mercury plummeting to a low of 18.5°F (-7.5°C) and highs barely crossing 31.1°F (-0.5°C). Cold winds sweep through the city, along with an increase in snowfall from November to 2.72" (69mm). 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
The most humid month in Roundup is January, with an average relative humidity of 77%.
January is the month with the least rainfall. Rain falls for 5.6 days and accumulates 0.55" (14mm) of precipitation.
Throughout the year, there are 114.3 rainfall days, and 12.13" (308mm) of precipitation is accumulated.
January through May, September through December are months with snowfall in Roundup.
In Roundup, during the entire year, snow falls for 53.5 days and aggregates up to 18.58" (472mm) of snow.
February is the month with the most snowfall. Snow falls for 11.1 days and accumulates 3.78" (96mm) of snow.
February and December, with an average of 5.2h of sunshine, are months with the least sunshine.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Roundup, 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.
The month with the most rainfall is May, when the rain falls for 15.6 days and typically aggregates up to 1.97" (50mm) of precipitation.
In Roundup, snow does not fall in June through August.
June has the longest days of the year, with an average of 15h and 48min of daylight.
Roundup's warmest month, July, generally records average temperatures ranging from a high of 84.7°F (29.3°C) to a low of 62.4°F (16.9°C).
July has the most sunshine of the year in Roundup, Montana, with an average of 11.8h of sunshine.
The month with the highest UV index in Roundup is July, with an average maximum UV index of 7.
August is the least humid month, with an average relative humidity of 39%.
During the coldest month in Roundup, December, temperatures average a high of 31.1°F (-0.5°C) and a low of 18.5°F (-7.5°C).
With an average of 8h and 42min of daylight, December has the shortest days of the year in Roundup, Montana.
With an average maximum UV index of 1, December is the month with the lowest UV index.
Average temperature
Roundup, MT
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is December (31.1°F).
The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is February (18°F).
Average pressure
Roundup, MT
- Average pressure in January:
30.13"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.92"Hg - Average pressure in June:
29.85"Hg
- Average pressure in July:
29.89"Hg - Average pressure in August:
29.89"Hg - Average pressure in September:
29.93"Hg - Average pressure in October:
29.99"Hg - Average pressure in November:
30.05"Hg - Average pressure in December:
30.12"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed
Roundup, MT
- Average wind speed in January:
11.2mph - Average wind speed in February:
10.2mph - Average wind speed in March:
9.9mph - Average wind speed in April:
10.7mph - Average wind speed in May:
10.2mph - Average wind speed in June:
9.4mph
- Average wind speed in July:
8.5mph - Average wind speed in August:
8.5mph - Average wind speed in September:
9.3mph - Average wind speed in October:
10.4mph - Average wind speed in November:
10.9mph - Average wind speed in December:
11mph
The windiest month (with the highest average wind speed) is January (11.2mph).
The calmest months (with the lowest average wind speed) are July and August (8.5mph).
Average humidity
Roundup, MT
The month with the highest relative humidity is January (77%).
The month with the lowest relative humidity is August (39%).
Average rainfall
Roundup, MT
- Average rainfall in January:
0.55" - Average rainfall in February:
0.59" - Average rainfall in March:
0.67" - Average rainfall in April:
1.65" - Average rainfall in May:
1.97" - Average rainfall in June:
1.89"
- Average rainfall in July:
0.83" - Average rainfall in August:
0.98" - Average rainfall in September:
0.94" - Average rainfall in October:
0.83" - Average rainfall in November:
0.63" - Average rainfall in December:
0.59"
The wettest month (with the highest rainfall) is May (1.97").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days
Roundup, MT
- Average rainfall days in January:
5.6 days - Average rainfall days in February:
4.6 days - Average rainfall days in March:
8.6 days - Average rainfall days in April:
13.9 days - Average rainfall days in May:
15.6 days - Average rainfall days in June:
13.9 days
- Average rainfall days in July:
11.9 days - Average rainfall days in August:
10.6 days - Average rainfall days in September:
8 days - Average rainfall days in October:
9.5 days - Average rainfall days in November:
6.6 days - Average rainfall days in December:
5.5 days
The month with the highest number of rainy days is May (15.6 days).
The month with the least rainy days is February (4.6 days).
Average snowfall
Roundup, MT
- Average snowfall in January:
3.15" - Average snowfall in February:
3.78" - Average snowfall in March:
1.77" - Average snowfall in April:
3.31" - Average snowfall in May:
0.87" - Average snowfall in June:
0"
The month with the highest snowfall is February (3.78").
The months with the least snowfall are June, July and August (0").
Average snowfall days
Roundup, MT
- Average snowfall days in January:
10.1 days - Average snowfall days in February:
11.1 days - Average snowfall days in March:
7.3 days - Average snowfall days in April:
5 days - Average snowfall days in May:
0.8 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0.3 days - Average snowfall days in October:
2.8 days - Average snowfall days in November:
6.5 days - Average snowfall days in December:
9.6 days
The month with the highest number of snowfall days is February (11.1 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight / Average sunshine
Roundup, 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 42min
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 42min).
- Average sunshine in January:
5h and 18min - Average sunshine in February:
5h and 12min - Average sunshine in March:
7h and 12min - Average sunshine in April:
8h and 54min - Average sunshine in May:
9h and 48min - Average sunshine in June:
11h and 12min
- Average sunshine in July:
11h and 48min - Average sunshine in August:
11h and 30min - Average sunshine in September:
10h and 12min - Average sunshine in October:
6h and 18min - Average sunshine in November:
6h and 6min - Average sunshine in December:
5h and 12min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The months with the least sunshine are February and December (Average sunshine: 5h and 12min).
Average sunshine days
Roundup, MT
- Average sunshine days in January:
18.4 days - Average sunshine days in February:
14.8 days - Average sunshine days in March:
16.3 days - Average sunshine days in April:
12.8 days - Average sunshine days in May:
13.6 days - Average sunshine days in June:
13.2 days
- Average sunshine days in July:
15.6 days - Average sunshine days in August:
15.8 days - Average sunshine days in September:
19.5 days - Average sunshine days in October:
17 days - Average sunshine days in November:
18.1 days - Average sunshine days in December:
17.8 days
The month with the most sunshine days is September (19.5 days).
The month with the least sunshine days is April (12.8 days).
Average UV index
Roundup, MT
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is December (UV index 1).
Average cloud cover
Roundup, 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 16).
Average visibility
Roundup, MT
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).
