Flight time & jet lag: Toronto to Seattle

Toronto to Seattle: Route overview

This medium-haul route from Toronto (YYZ) to Seattle (SEA) covers 3,307 km in approximately 4h 23m to 5h 04m, crossing 3 time zones westbound. The 3-hour westbound shift means your body clock will be noticeably out of sync for 2–3 days, affecting sleep quality, appetite, and concentration at your destination. Both cities sit at similar temperate latitudes, meaning daylight patterns will feel familiar upon arrival — a helpful factor for circadian adjustment.

What makes the Toronto–Seattle route different

The specific combination of 3,307 km distance, 3-hour time difference, and westbound direction places this route in the moderate jet lag category. Compared to a same-distance route with fewer time zones crossed, the circadian challenge here is the dominant factor in post-arrival recovery.

Arrival strategy for Seattle

Arriving in Seattle after a 3-hour westward shift gives you a slightly longer day. Your body clock will be 3 hours ahead of local time, so you may feel sleepy earlier than locals. Compensate by seeking bright afternoon and evening light in Seattle, which helps delay your body clock. Try to stay awake until at least 21:00 local time on your first evening.

Circadian rhythm analysis: Toronto → Seattle

When you arrive in Seattle, your circadian rhythm is still running on Toronto time. At 09:00 Seattle time, your body reads 12:00 — 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 01:00 — 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 Seattle (day 1)

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

Pre-departure preparation

For this 3-hour westward shift to Seattle, start 3 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 Seattle's daytime. This gradual shift can significantly ease your transition upon arrival.

Your first 72 hours in Seattle

Day 1 in Seattle: Your body is ~3 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: ~2 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 Toronto → Seattle 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 Seattle's schedule.

Route Planner

Adjust departure date for DST-accurate results.

Jet lag adjustment plan: Toronto → Seattle

Noticeable fatigue and sleep disruption for 2–3 days. Plan for adjustment.

Business hours: Toronto vs Seattle

Seasonal and climate factors

Flight times between Toronto and Seattle can vary by 15–30 minutes seasonally due to shifting wind patterns along this medium-haul corridor. Seattle at 47°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 Toronto–Seattle flight time is estimated

The 4h 23m to 5h 04m estimate for Toronto to Seattle is derived from the 3,307-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 YYZ and SEA. 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 Toronto–Seattle 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 Toronto (Canada) with Seattle (United States). Most travelers on stays of 3 days or longer will benefit from fully adjusting to Seattle's local time, as the 3-hour shift is manageable within the first 2–3 days with proper light and sleep management.

Frequently asked questions: Toronto to Seattle

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