Best Time to Drive: Sidney, MT to Evergreen, MT

The best overall window to drive from Sidney, MT to Evergreen, MT is May to June. May is especially comfortable, and 8 AM to 11 AM is usually the easiest departure window. The main things to watch are heavy rain and ponding.

Best overall window

May to June

This stretch gives the steadiest mix of comfort, daylight, and lower weather friction.

Easiest departure pattern

8 AM to 11 AM

Mid-morning is usually the steadiest all-around departure window.

Most challenging stretch

January to February

November is one of the harder months for this route because the weather friction stacks up faster.

Why This Route Scores Differently

This route is long enough that weather comfort across the whole day matters more than just departure conditions.

The current best window is May to June, when the drive is more likely to feel steady end to end.

This score uses multiple NOAA sample points along the route instead of a single state-wide climate average.

Month-by-Month Driving Conditions

Jan

Challenging 28°F

Feb

Challenging 29°F

Mar

Challenging 35°F

Apr

Good 42°F

May

Good 48°F

Jun

Good 54°F

Jul

Good 57°F

Aug

Great 56°F

Sep

Fair 50°F

Oct

Fair 43°F

Nov

Challenging 35°F

Dec

Challenging 30°F

Best Good/Fair Challenging

Average Conditions by Month

January

Avg high / low 35 / 20°F

Moisture 3.8 in rain

Rating Challenging

Best departure

9 AM to 12 PM

Winter mix risk

Temperatures are workable, but not as easy as the best shoulder-season windows.

Weather is mixed enough that departure timing still matters.

February

Avg high / low 38 / 20°F

Moisture 3.1 in rain

Rating Challenging

Best departure

9 AM to 12 PM

Winter mix risk

Temperatures are workable, but not as easy as the best shoulder-season windows.

Weather is mixed enough that departure timing still matters.

March

Avg high / low 44 / 25°F

Moisture 4 in rain

Rating Challenging

Best departure

9 AM to 12 PM

Winter mix risk

Temperatures are workable, but not as easy as the best shoulder-season windows.

Weather is mixed enough that departure timing still matters.

April

Avg high / low 52 / 31°F

Moisture 3.9 in rain

Rating Good

Best departure

9 AM to 12 PM

Steady driving window

Temperatures are workable, but not as easy as the best shoulder-season windows.

Weather is mixed enough that departure timing still matters.

May

Avg high / low 57 / 39°F

Moisture 4.2 in rain

Rating Good

Best departure

8 AM to 11 AM

Wet stretches

Temperatures are workable, but not as easy as the best shoulder-season windows.

Weather is mixed enough that departure timing still matters.

June

Avg high / low 62 / 45°F

Moisture 4.7 in rain

Rating Good

Best departure

8 AM to 11 AM

Wet stretches Patchy fog

Daytime temperatures usually stay in a comfortable driving range.

Weather is mixed enough that departure timing still matters.

July

Avg high / low 65 / 49°F

Moisture 4.7 in rain

Rating Good

Best departure

8 AM to 11 AM

Wet stretches Patchy fog Holiday traffic

Daytime temperatures usually stay in a comfortable driving range.

Weather is mixed enough that departure timing still matters.

August

Avg high / low 64 / 47°F

Moisture 4.3 in rain

Rating Great

Best departure

8 AM to 11 AM

Wet stretches

Daytime temperatures usually stay in a comfortable driving range.

Weather is mixed enough that departure timing still matters.

September

Avg high / low 59 / 42°F

Moisture 5.1 in rain

Rating Fair

Best departure

7 AM to 10 AM

Storm-prone Patchy fog

Temperatures are workable, but not as easy as the best shoulder-season windows.

Rain is common enough that extra buffer time makes sense.

October

Avg high / low 52 / 33°F

Moisture 3.4 in rain

Rating Fair

Best departure

9 AM to 12 PM

Steady driving window

Temperatures are workable, but not as easy as the best shoulder-season windows.

Weather is mixed enough that departure timing still matters.

November

Avg high / low 44 / 25°F

Moisture 3.5 in rain

Rating Challenging

Best departure

9 AM to 12 PM

Holiday traffic

Temperatures are workable, but not as easy as the best shoulder-season windows.

Weather is mixed enough that departure timing still matters.

December

Avg high / low 38 / 22°F

Moisture 3.9 in rain

Rating Challenging

Best departure

9 AM to 12 PM

Winter mix risk Holiday traffic

Temperatures are workable, but not as easy as the best shoulder-season windows.

Weather is mixed enough that departure timing still matters.

Seasonal Hazards on This Route

Heavy rain and ponding

Sep

Short intense downpours can make a same-day drive feel longer than the raw route time suggests.

Winter mix risk

Jan - Dec

Even light snow or freezing precipitation can matter more than usual when this route turns into a same-day commitment.

Best Departure Time by Season

Spring

9 AM to 12 PM

Waiting for a little daylight and warmer pavement usually makes the drive easier.

Summer

8 AM to 11 AM

Mid-morning is usually the steadiest all-around departure window.

Fall

9 AM to 12 PM

Waiting for a little daylight and warmer pavement usually makes the drive easier.

Winter

9 AM to 12 PM

Waiting for a little daylight and warmer pavement usually makes the drive easier.

How This Score Was Built

Source

Route-sampled NOAA climate normals

High confidence. Built from 4 NOAA-backed route checkpoints rather than a single statewide estimate.

Origin zone

Mountain West

Destination zone

Mountain West

Route sample points

Late route

Late route checkpoint

VA ROCKY MT (1435 mi away)

Late route

Late route checkpoint

NC ROCKY MT (1726.9 mi away)

Late route

Late route checkpoint

VA ROCKY MT (1845.3 mi away)

Destination

Evergreen, MT

VA ROCKY MT (1893.2 mi away)

Ready to plan? See the full trip plan from Sidney, MT to Evergreen, MT with stops, fuel costs, and directions.

Considering flying instead? Compare driving vs flying for this route.