– Lat/Long: 47.51° N 121.74° W

Mount Si
Weather Forecast, United States
Issued: 10 am Tue 12 May Local Time
Updates in:
hr min s
Update imminent

Issued: 10 am Tue 12 May Local Time

Updates in:

hr min s

Update imminent

2 Mount Si Elevations: 2 Forecast Elevations:

	Days 1–3 Weather Summary Mild with moderate rain (total 18mm) on Tue night, Becoming colder with a light covering of snow, mostly falling on Wed morning. Very mild (max 19°C on Tue afternoon, min 1°C on Wed morning). Winds increasing (light winds from the S on Tue afternoon, near gales from the WSW by Wed afternoon).									Days 4–6 Weather Summary A moderate fall of snow, heaviest on Sat night. Freeze-thaw conditions (max 3°C on Sun night, min -3°C on Sat night). Winds decreasing (fresh winds from the WSW on Sat afternoon, calm by Sun night).
	Tuesday 12			Wednesday 13			Thursday 14			Friday 15			Saturday 16			Sunday 17
	AM	PM	night	AM	PM	night	AM	PM	night	AM	PM	night	AM	PM	night	AM	PM	night

	some clouds	rain shwrs	rain shwrs	light snow	mod. rain	light rain	some clouds	light rain	rain shwrs	some clouds	cloudy	snow shwrs	snow shwrs	light snow	mod. snow	light snow	some clouds	rain shwrs
km/h	ESE	W	WSW	WSW	WSW	WSW	WSW	WSW	WSW	SW	WSW	WSW	SW	WSW	NNW	NNW	NW	W
See all weather maps
cm	—	—	—	5	—	—	—	—	—	—	—	2	2	3	9	1	—	—
mm	—	0.1	10	—	6	0.7	—	1	0.5	—	—	—	—	—	—	—	—	0.1
max °C	16	19	12	2	4	3	2	4	2	0	2	1	0	1	-1	-1	1	3
min °C	15	16	4	1	2	1	1	3	1	0	1	0	0	0	-3	-2	0	1
chill °C	14	16	0	-4	-4	-6	-5	-2	-6	-6	-5	-7	-6	-7	-9	-8	-4	-2

Freezing level m	3800	3650	3050	1550	1950	1450	1550	1700	1500	1300	1450	1200	1300	1250	800	1050	1400	1600
Cloud base (m)	5700	6250	700	450	400	450	700	900	450	700	900	400	650	450	400	450	550	950

	5:33	—	—	5:31	—	—	5:31	—	—	5:30	—	—	5:28	—	—	5:26	—	—
	—	—	8:32	—	—	8:34	—	—	8:35	—	—	8:37	—	—	8:37	—	—	8:38

Mount Si Weather (Days 0-3):

The weather forecast for Mount Si is: Mild with moderate rain (total 18mm) on Tue night, Becoming colder with a light covering of snow, mostly falling on Wed morning. Very mild (max 19°C on Tue afternoon, min 1°C on Wed morning). Winds increasing (light winds from the S on Tue afternoon, near gales from the WSW by Wed afternoon).

Mount Si Weather (Days 3-6):

A moderate fall of snow, heaviest on Sat night. Freeze-thaw conditions (max 3°C on Sun night, min -3°C on Sat night). Winds decreasing (fresh winds from the WSW on Sat afternoon, calm by Sun night).

This table gives the weather forecast for Mount Si at the specific elevation of 1270 m. Our advanced weather models allow us to provide distinct weather forecasts for several elevations of Mount Si. To see the weather forecasts for the other elevations, use the tab navigation above the table. For a wider overview of the weather, consult the Weather Map of Washington.

Live conditions reported by 10 closest weather stations

Weather Station	Temp.	Weather	Wind	Cloud Visibility Cloud / Visibility
Harman Heights wx 6 km SSW 251m alt. 44 minutes ago	28° C	Dry	Calm (0 kph at 314).
Renton 30 km WSW 160m alt. 1 hour ago	27° C	Dry	Calm (3 kph at 265).
Black Diamond 32 km SSW 192m alt. 47 minutes ago		-	Wind obs. (6 kph from 360 degs) was rejected.
Grotto wx 35 km NE 321m alt. 1 hour ago	33° C	Dry	Light winds from the ESE (6 kph at 114).
Renton Airport 36 km WSW 218m alt. 2 hours ago	24° C	Dry and partly cloudy.	Light winds from the N (6 kph at 350).	16 km Low: scattered
Grotto wx 39 km NE 1101m alt. 42 minutes ago	25° C	Dry	Calm (3 kph at 120).
Auburn 39 km SW 119m alt. 1 hour ago	36° C	Dry	Calm (2 kph at 107).
Stampede Pass Airport 40 km SE 628m alt. 2 hours ago	21° C	Clear	Calm (0 kph at 0).	16 km
SHIP3629 43 km W 15m alt. 2 hours ago				- km
SHIP4784 43 km W 3m alt. 2 hours ago	23° C

* NOTE: not all weather observatories update at the same frequency which is the reason why some locations may show data from stations that are further away than known closer ones.