I-405 South Traffic in Seattle

As of 11:45 pm PDT, I-405 South in Seattle is averaging 62 mph across 59 sensors.

Is I-405 South moving right now?

Yes. No stretch of I-405 South in Seattle is under 40 mph right now (as of 11:45 pm PDT).

Best time to drive I-405 South

Traffic is usually worst on Tuesday around 8 am (about 49 mph). On weekdays the morning slowdown peaks around 8 am (49 mph on Tuesdays) and the evening slowdown around 4 pm (54 mph on Fridays). Midday (10 am to 2 pm) averages 59 mph. On weekends it is slowest on Saturdays around 5 pm (59 mph).

Typical average speed (mph) on I-405 South in Seattle, by day and hour (local time)
Day	5am	6am	7am	8am	9am	10am	11am	12pm	1pm	2pm	3pm	4pm	5pm	6pm	7pm	8pm	9pm
Mon	62	58	54	52	54	60	62	61	60	58	57	57	–	60	62	62	62
Tue	61	57	52	49	50	57	61	61	60	58	57	57	56	58	60	62	–
Wed	62	57	53	50	53	58	61	60	–	58	–	–	54	58	–	62	62
Thu	62	57	53	51	52	57	60	61	59	57	56	–	54	58	59	62	62
Fri	61	58	56	56	57	58	58	58	57	56	54	54	56	59	61	61	62
Sat	–	–	–	–	–	–	–	–	–	59	59	59	59	60	60	61	61
Sun	60	61	61	61	61	61	61	60	60	–	61	61	61	61	61	–	–

Averages of every 5-minute reading we have recorded at this time of the week. Colors match the live map.

Questions

When is traffic worst on I-405 South in Seattle?

Traffic on I-405 South is usually worst on Tuesday around 8 am (about 49 mph).

What is the best time to drive I-405 South in Seattle?

On weekdays, avoid around 8 am (49 mph on Tuesdays) and around 4 pm (54 mph on Fridays). Midday (10 am to 2 pm) averages 59 mph, and early mornings and late evenings are fastest.

Is I-405 South busy right now?

As of 11:45 pm PDT, I-405 South in Seattle is averaging 62 mph across 59 sensors.

Plan ahead: Seattle traffic tomorrow · Traffic estimator

Other freeways in Seattle

US-2 East · US-2 West · I-5 North · I-5 South · SR-9 North · SR-9 South · SR-16 East · SR-16 West · SR-18 East · SR-18 West · I-90 East · I-90 West · SR-99 North · SR-99 South · SR-167 North · SR-167 South · I-405 North · SR-509 North · SR-509 South · SR-512 East · SR-512 West · SR-520 East · SR-520 West · SR-522 East · SR-522 West · SR-525 North · SR-525 South

Day	5am	6am	7am	8am	9am	10am	11am	12pm	1pm	2pm	3pm	4pm	5pm	6pm	7pm	8pm	9pm
Mon	62	58	54	52	54	60	62	61	60	58	57	57	–	60	62	62	62
Tue	61	57	52	49	50	57	61	61	60	58	57	57	56	58	60	62	–
Wed	62	57	53	50	53	58	61	60	–	58	–	–	54	58	–	62	62
Thu	62	57	53	51	52	57	60	61	59	57	56	–	54	58	59	62	62
Fri	61	58	56	56	57	58	58	58	57	56	54	54	56	59	61	61	62
Sat	–	–	–	–	–	–	–	–	–	59	59	59	59	60	60	61	61
Sun	60	61	61	61	61	61	61	60	60	–	61	61	61	61	61	–	–

Day	5am	6am	7am	8am	9am	10am	11am	12pm	1pm	2pm	3pm	4pm	5pm	6pm	7pm	8pm	9pm
Mon	62	58	54	52	54	60	62	61	60	58	57	57	–	60	62	62	62
Tue	61	57	52	49	50	57	61	61	60	58	57	57	56	58	60	62	–
Wed	62	57	53	50	53	58	61	60	–	58	–	–	54	58	–	62	62
Thu	62	57	53	51	52	57	60	61	59	57	56	–	54	58	59	62	62
Fri	61	58	56	56	57	58	58	58	57	56	54	54	56	59	61	61	62
Sat	–	–	–	–	–	–	–	–	–	59	59	59	59	60	60	61	61
Sun	60	61	61	61	61	61	61	60	60	–	61	61	61	61	61	–	–

Day	5am	6am	7am	8am	9am	10am	11am	12pm	1pm	2pm	3pm	4pm	5pm	6pm	7pm	8pm	9pm
Mon	62	58	54	52	54	60	62	61	60	58	57	57	–	60	62	62	62
Tue	61	57	52	49	50	57	61	61	60	58	57	57	56	58	60	62	–
Wed	62	57	53	50	53	58	61	60	–	58	–	–	54	58	–	62	62
Thu	62	57	53	51	52	57	60	61	59	57	56	–	54	58	59	62	62
Fri	61	58	56	56	57	58	58	58	57	56	54	54	56	59	61	61	62
Sat	–	–	–	–	–	–	–	–	–	59	59	59	59	60	60	61	61
Sun	60	61	61	61	61	61	61	60	60	–	61	61	61	61	61	–	–