Climbing Forecast › I-90 Corridor › Little Si

I-90 CORRIDOR · METAMORPHIC

Little Si climbing conditions

Good — dry and climbable

Right now

Temp53°F
Wind7 mph
Gusts10 mph
Humidity88.8%
Rain 48hdry
Last rainNone recent

Assessment

No recent rain
Good friction temperature range for metamorphic
High humidity (88.8%) — metamorphic friction compromised, particularly for bouldering

7-day forecast

Scroll through each day — hourly detail is shown inline.

Today Sunday 4 October
Good
Temp48°F
Raindry
Wind6 mph
Gusts10 mph
Humidity86%
No recent rain
  • Metamorphic rock climbs well when dry; tree cover can slow drying
  • Damp air — friction edges may feel greasy
Time °F Rain Wind (mph) Gust Hum
06:00 51° dry 7 — 88.9%
07:00 50° dry 6 — 89.3%
08:00 49° dry 6 — 89.3%
09:00 49° dry 6 — 89.7%
10:00 49° dry 6 — 87.9%
11:00 48° dry 6 — 87%
12:00 48° dry 6 — 87.3%
13:00 47° dry 6 — 88.1%
14:00 46° dry 5 — 89.5%
15:00 48° dry 5 — 86%
16:00 57° dry 5 — 73.2%
17:00 64° dry 3 — 59.6%
18:00 68° dry 3 — 54.5%
19:00 69° dry 4 — 54.7%
20:00 71° dry 4 — 54.6%
21:00 71° dry 4 — 53.7%
Mon Monday 5 October
Good
Temp50°F
Raindry
Wind2 mph
Gusts—
Humidity88%
No recent rain
  • Metamorphic rock climbs well when dry; tree cover can slow drying
  • Damp air — friction edges may feel greasy
Time °F Rain Wind (mph) Gust Hum
06:00 53° dry 2 — 86.5%
07:00 53° dry 1 — 85.4%
08:00 52° dry 2 — 87.4%
09:00 50° dry 2 — 91.2%
10:00 49° dry 2 — 92.6%
11:00 48° dry 1 — 92.2%
12:00 49° dry 1 — 91.1%
13:00 49° dry 1 — 88.7%
14:00 50° dry 1 — 86.6%
15:00 52° dry 2 — 84.9%
16:00 57° dry 2 — 77.2%
17:00 59° dry 2 — 77.1%
18:00 62° dry 3 — 74.4%
19:00 64° dry 4 — 70.3%
20:00 65° dry 6 — 66.8%
21:00 66° dry 8 — 66.1%
Tue Tuesday 6 October
Caution
Temp46°F
Raindry
Wind2 mph
Gusts—
Humidity91%
No recent rainHumidity 91% — potential fog
  • Metamorphic rock climbs well when dry; tree cover can slow drying
  • Damp air — friction edges may feel greasy
Time °F Rain Wind (mph) Gust Hum
06:00 49° dry 4 — 97%
07:00 48° dry 4 — 96.1%
08:00 47° dry 4 — 95.5%
09:00 47° dry 4 — 96%
10:00 46° dry 4 — 95.6%
11:00 45° dry 4 — 94.6%
12:00 45° dry 3 — 93.5%
13:00 44° dry 2 — 91.7%
14:00 44° dry 2 — 90.9%
15:00 46° dry 2 — 87.5%
16:00 52° dry 2 — 80%
17:00 56° dry 2 — 70.6%
18:00 59° dry 3 — 66.1%
Wed Wednesday 7 October
Poor
Temp41°F
Raindry
Wind2 mph
Gusts—
Humidity97%
No recent rainHumidity 97% — likely fog/cloud
  • Metamorphic rock climbs well when dry; tree cover can slow drying
  • Damp air — friction edges may feel greasy
Time °F Rain Wind (mph) Gust Hum
06:00 47° dry 1 — 94.1%
12:00 42° dry 2 — 96.7%
18:00 61° dry 3 — 61.8%
Thu Thursday 8 October
Good
Temp46°F
Raindry
Wind2 mph
Gusts—
Humidity88%
No recent rain
  • Metamorphic rock climbs well when dry; tree cover can slow drying
  • Damp air — friction edges may feel greasy
Time °F Rain Wind (mph) Gust Hum
06:00 48° dry 2 — 94.2%
12:00 47° dry 2 — 88.1%
18:00 62° dry 2 — 60.9%
Fri Friday 9 October
Poor
Temp48°F
Rain0.07 in
Wind3 mph
Gusts—
Humidity91%
1.9mm rain forecastHumidity 91% — potential fog
  • Wet metamorphic rock is slick — some overhung walls stay climbable
  • Damp air — friction edges may feel greasy
Time °F Rain Wind (mph) Gust Hum
06:00 51° dry 2 — 89.9%
12:00 48° 0.02 in 3 — 91.2%
18:00 51° 0.06 in 7 — 97.7%
Sat Saturday 10 October
Poor
Temp45°F
Rain0.05 in
Wind1 mph
Gusts—
Humidity92%
1.2mm rain forecastHumidity 92% — potential fog
  • Wet metamorphic rock is slick — some overhung walls stay climbable
  • Damp air — friction edges may feel greasy
Time °F Rain Wind (mph) Gust Hum
06:00 46° dry 2 — 96.1%
12:00 44° dry 1 — 91.7%
18:00 47° 0.00 in 4 — 90.9%
Sun Sunday 11 October
Good
Temp36°F
Raindry
Wind2 mph
Gusts—
Humidity84%
Should be dry
  • Metamorphic rock climbs well when dry; tree cover can slow drying
Time °F Rain Wind (mph) Gust Hum
06:00 40° dry 3 — 96.2%
12:00 35° dry 3 — 83.7%
18:00 50° dry 3 — 39.8%

About Little Si

Little Si sits below Mount Si at the western edge of the Cascades, an hour east of Seattle, and holds the region's steepest sport climbing. Access via Exit 32 off I-90 and a 30-minute hike up the popular Little Si trail through old-growth Douglas fir. World Wall's overhanging cave routes stay dry in rain and make it a genuine year-round crag for climbers pulling 5.12 and harder; Interstate Park offers steep pump-fests in the 5.10–5.12 range. The volcanic metamorphic rock ranges from bullet-hard, textured pinches on the steep walls to slick, sharper stone on the slabs. April through October is the fair-weather season, but the World Wall's angle means winter climbing is a real option. Mount Si NRCA trailhead — Washington Discover Pass required.

Region
I-90 Corridor
Rock type
Metamorphic
Aspect
north-east-facing
Altitude
1184 ft
Exposure
medium
Seepage
medium

Other crags in this region

Exit 38 (Deception Crags)