Sites/Mt. Umunhum
DOSSIER · 623SITE · NORTH AMERICA
37°09′17″N · 121°53′55″WLIVE CHART · OBSERVED 1402Z
Airworthy · 3+
NORTH AMERICA · CALIFORNIA · USA

Mt. Umunhum

ThermalRidgeXCSimulatedFoot Launch
ELEV 1,055 M / 3,460 FTTZ Pacific Daylight Time

Specimen Sheet · Vital Statistics

Launch Elev1,055 m
Launch Elev FT3,460 ft MSL
Min Hang RatingH3
Best Wind0° · 0–0 kt
Coordinates37.1548° N
 -121.8986° E

Classification · Terrain & Access

Foot Launch
§ 01CHART · LAUNCHES & LANDINGS

Field chart.

Launch point
Landing zone
Launch heading
1 LAUNCH · 1 LZ · ALT RANGE 3251,055 M

§ 02 · Flying Conditions · Field NotesUpdated 2026·03·21

This is an old military site with lots of toxic material being cleaned up, but will soon be opened up for recreational use including free flight. Now is our chance to simulate some flights on it, and figure out the ideal LZ's and XC routes for various wind conditions.

South facing launches are less steep but have an easier glide out to bailout areas. North west facing launch are steeper and the ridge is better, but it is a long way to an LZ

Has 1 different launch points. The best wind direction is 0 @ 0 knts but many sites can be flown from multiple directions, so check before you fly.

You can expect to find: thermal conditions ridge soaring conditions cross country potential , all dependent on current weather conditions.

§ 03 · Wind Window · Best Operating EnvelopeN · 000° ±0°

NSEWNESENWSW
00 kt
Primary · N · 000°
Envelope: 000° – 000° (±0°)
Preferred · 00 ktWorkable · 03 ktHazardous · >5 kt

Chase the Wind

Nearest weather station to Mt. Umunhum. Select any row to see which launches are in wind, then set your MSFS world clock to that UTC time.

San Jose/Reid-Hillview Arpt, CA, US

13:43 UTC

21 km from site

Wind

Calm

0 kt

Ceiling

SCT 0 ft

10+ sm vis

Calm · 0 kt · 13:43 UTC

West from top of ridge (best)Calm / Var

Select a time to check launches

Jan 21

Weather at , 21 km from Mt. Umunhum. Mountain conditions may differ — this is a clue, not a forecast. Adjust sim time on site until conditions feel right.

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§ 07 · Location · Field CoordinatesWGS-84

Latitude37.154750
Longitude-121.898588
DMS · N37°09′17″N
DMS · E121°53′55″W
Altitude1,055 m
Altitude FT3,460 ft
Time ZonePacific Daylight Time
UTM10S 597 802 E · 4 352 551 N

§ 09 · Recent Flights · Log Book

No flights logged at Mt. Umunhum yet.

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FILE № 623 · CLOSED 2026·03·21
THE HANG GLIDING FILES · THGF
✎ SURVEYED · NORTH AMERICA · USA