Best Time to Drive: Boulder, CO to Delta, CO

The best overall window to drive from Boulder, CO to Delta, CO is April to June. May is especially comfortable, and 8 AM to 11 AM is usually the easiest departure window. The main things to watch are summer heat load.

Best overall window

April 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

December

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

Why This Route Scores Differently

You can usually do this in one long day, which makes daylight and storm timing more important than hotel planning.

The current best window is April 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

Fair 32°F

Feb

Fair 33°F

Mar

Good 42°F

Apr

Great 48°F

May

Excellent 57°F

Jun

Great 68°F

Jul

Good 75°F

Aug

Great 73°F

Sep

Excellent 65°F

Oct

Great 51°F

Nov

Fair 39°F

Dec

Fair 31°F

Best Good/Fair Challenging

Average Conditions by Month

January

Avg high / low 45 / 19°F

Moisture 0.4 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.

Rain disruption is usually limited compared with wetter months.

February

Avg high / low 46 / 20°F

Moisture 0.4 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.

Rain disruption is usually limited compared with wetter months.

March

Avg high / low 56 / 28°F

Moisture 0.9 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.

Rain disruption is usually limited compared with wetter months.

April

Avg high / low 62 / 34°F

Moisture 1.7 in rain

Rating Great

Best departure

9 AM to 12 PM

Steady driving window

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

Rain disruption is usually limited compared with wetter months.

May

Avg high / low 71 / 44°F

Moisture 2.2 in rain

Rating Excellent

Best departure

8 AM to 11 AM

Steady driving window

Daytime temperatures usually stay in a comfortable driving range.

Rain disruption is usually limited compared with wetter months.

June

Avg high / low 83 / 53°F

Moisture 1.9 in rain

Rating Great

Best departure

8 AM to 11 AM

Steady driving window

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

Rain disruption is usually limited compared with wetter months.

July

Avg high / low 90 / 60°F

Moisture 2.1 in rain

Rating Good

Best departure

8 AM to 11 AM

Warm afternoons Holiday traffic

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

Rain disruption is usually limited compared with wetter months.

August

Avg high / low 88 / 58°F

Moisture 1.6 in rain

Rating Great

Best departure

8 AM to 11 AM

Warm afternoons

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

Rain disruption is usually limited compared with wetter months.

September

Avg high / low 80 / 50°F

Moisture 1.4 in rain

Rating Excellent

Best departure

8 AM to 11 AM

Steady driving window

Daytime temperatures usually stay in a comfortable driving range.

Rain disruption is usually limited compared with wetter months.

October

Avg high / low 65 / 37°F

Moisture 1 in rain

Rating Great

Best departure

8 AM to 11 AM

Steady driving window

Daytime temperatures usually stay in a comfortable driving range.

Rain disruption is usually limited compared with wetter months.

November

Avg high / low 53 / 26°F

Moisture 0.6 in rain

Rating Fair

Best departure

9 AM to 12 PM

Holiday traffic

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

Rain disruption is usually limited compared with wetter months.

December

Avg high / low 44 / 18°F

Moisture 0.3 in rain

Rating Fair

Best departure

9 AM to 12 PM

Holiday traffic

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

Rain disruption is usually limited compared with wetter months.

Seasonal Hazards on This Route

Summer heat load

Jul

Very warm afternoons increase driver fatigue and make tire, coolant, and water planning more important.

Best Departure Time by Season

Spring

8 AM to 11 AM

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

Summer

8 AM to 11 AM

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

Fall

8 AM to 11 AM

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

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 3 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

CO statewide fallback (0 mi away)

Late route

Late route checkpoint

CO statewide fallback (0 mi away)

Destination

Delta, CO

CO statewide fallback (0 mi away)

Ready to plan? See the full trip plan from Boulder, CO to Delta, CO with stops, fuel costs, and directions.

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