Flight time & jet lag: Chicago to San Francisco

Chicago to San Francisco: Route overview

This medium-haul route from Chicago (ORD) to San Francisco (SFO) covers 2,964 km in approximately 3h 59m to 4h 38m, crossing 2 time zones westbound. With only a 2-hour time difference, most travelers adjust within a day, though the medium-haul journey may still cause travel fatigue. Both cities sit at similar temperate latitudes, meaning daylight patterns will feel familiar upon arrival — a helpful factor for circadian adjustment.

What makes the Chicago–San Francisco route different

With only 2 hours of time difference, this route sits at the threshold where jet lag is barely noticeable for most travelers. The bigger factor is likely the 3h 59m to 4h 38m flight duration itself and any associated sleep deprivation.

Arrival strategy for San Francisco

Arriving in San Francisco after a 2-hour westward shift gives you a slightly longer day. Your body clock will be 2 hours ahead of local time, so you may feel sleepy earlier than locals. Compensate by seeking bright afternoon and evening light in San Francisco, which helps delay your body clock. Try to stay awake until at least 21:00 local time on your first evening.

Circadian rhythm analysis: Chicago → San Francisco

When you arrive in San Francisco, your circadian rhythm is still running on Chicago time. At 09:00 San Francisco time, your body reads 11:00 — a reasonable waking hour internally, so morning performance should be manageable. The main westbound challenge is that by 22:00 local, your body clock reads 00:00 — the deep night on your internal clock. You will feel intensely sleepy well before the local bedtime. Your circadian system adjusts at roughly 1 to 1.5 hours per day, so expect 2 days for full alignment.

Your body clock in San Francisco (day 1)

How your body clock maps to local time upon arrival, before any adjustment.

Pre-departure preparation

For this 2-hour westward shift to San Francisco, start 2 days before departure by delaying your bedtime by 60 minutes each night. Seek bright light in the evening hours to help push your clock later. On the flight, try to stay awake if arriving during San Francisco's daytime. This gradual shift can significantly ease your transition upon arrival.

Your first 72 hours in San Francisco

Day 1 in San Francisco: Your body is ~2 hours off local time. Stay active and seek afternoon sunlight. Push bedtime to at least 21:00 local. Eat at local mealtimes even if not hungry. Caffeine is fine before 16:00, not after. Day 2: ~1 hours off. Continue late afternoon (15:00–18:00) light exposure. Sleep quality should improve. Day 3: ~0 hours off. You should feel mostly adjusted. Return to normal activities.

Recovery timeline

Full circadian adjustment for the Chicago → San Francisco route typically takes 2 days, based on the body's natural adaptation rate of ~1 to 1.5 hours per day for westbound travel. During this period, expect gradually improving sleep quality, with the most noticeable symptoms (fatigue, difficulty concentrating, appetite changes) during the first 2 days. By day 2, most travelers report feeling fully synchronized with San Francisco's schedule.

Route Planner

Adjust departure date for DST-accurate results.

Business hours: Chicago vs San Francisco

Seasonal and climate factors

Flight times between Chicago and San Francisco can vary by 15–30 minutes seasonally due to shifting wind patterns along this medium-haul corridor. San Francisco at 38°N experiences moderate seasonal daylight variation. Summer offers longer evenings useful for westward adjustment, while winter's earlier sunsets support eastward adjustment schedules.

How the Chicago–San Francisco flight time is estimated

The 3h 59m to 4h 38m estimate for Chicago to San Francisco is derived from the 2,964-km great-circle distance. Medium-haul flights balance cruise and non-cruise phases, achieving effective speeds of 780–850 km/h. An additional 30–50 minutes accounts for taxi, takeoff, climb, descent, approach, and taxi at both ORD and SFO. Actual routing through controlled airspace may add 3–8% distance beyond the great-circle path due to air traffic corridors and restricted zones along the way.

Wind patterns and flight duration

Prevailing winds along the Chicago–San Francisco corridor have a moderate effect on flight time. Westbound flights may encounter mild headwinds from the general west-to-east upper atmospheric flow.

Practical travel context

This medium-haul route connects Chicago (United States) with San Francisco (United States).

Frequently asked questions: Chicago to San Francisco

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