Climate Comparison

Seongnam, South Korea vs. Silicon Valley, CA

East Asia

Seongnam, South Korea

Classification Dwa / Cwa (Continental)

Influenced heavily by the Siberian High in winter and the East Asian Monsoon in summer. Features four dramatically distinct seasons ranging from freezing, dry winter winds to hot, tropical, and heavily wet summer periods.

Extreme Winter Avg

Extreme Summer Avg

California, USA

Silicon Valley

Classification Csb (Mediterranean)

Covers Palo Alto, Mountain View, and Sunnyvale. Strongly moderated by the Pacific Ocean and SF Bay. Characterized by exceptional thermal stability, featuring comfortable, arid summers and mild, green winters.

Mild Winter Avg

Comfortable Summer Avg

Monthly Average Temperatures

Comparison of seasonal trajectory throughout the year

Direct Climate Metrics

Side-by-side core meteorological values

Key Metric Seongnam, South Korea Silicon Valley (Sunnyvale, MV, Palo Alto)
Hottest Month August
August / September
Coldest Month January
December / January
Annual Precipitation ~50.4 inches (1,281 mm)
Heavily concentrated in summer
~14.5 inches (368 mm)
Heavily concentrated in winter
Precipitation Pattern Summer Monsoon (*Jangma*)
July alone receives ~12.8 inches (324 mm)
Winter Storm Tracks
Dry summers (June–Sept average < 0.1 inches)
Snowfall Regular winter snowfall
Precipitation falls as snow from Dec to Feb
Extremely Rare / None
Temps almost never dip to freezing at valley floor
Relative Humidity Highly Variable
Uncomfortably high (80%+) in July/August
Consistently Moderate
Dry, comfortable summer afternoons (40%–50%)

Seasonal Dynamics

How the weather changes quarter by quarter

Winter (Dec–Feb)

Seongnam

Freezing, crisp, and dry. Dominated by cold continental winds from Siberia. Frequent frost and light-to-moderate snow.

Silicon Valley

Cool, green, and periodically rainy. Mild daytime temperatures mean snow is non-existent on the valley floor.

Spring (Mar–May)

Seongnam

Rapid warming with cherry blossom season. Pleasant temperatures, but occasionally affected by desert dust winds.

Silicon Valley

Pleasant, sunny, and highly comfortable. Rains quickly transition into dry, sunny spring afternoons in the 70s.

Summer (Jun–Aug)

Seongnam

Hot, humid, and rainy. The monsoon brings persistent tropical downpours and high heat indices that make it feel muggy.

Silicon Valley

Warm, bone-dry, and sunny. Absolute absence of rain, with cooling marine layers keeping humidity exceptionally comfortable.

Autumn (Sep–Nov)

Seongnam

Crisp, clear sky conditions with brilliant fall colors. Cooling temperatures, dropping rapidly as November approaches.

Silicon Valley

Extended summer-like conditions through September and October. Gentle transitions with late-year rain beginning in late November.