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Weather on December 17

Sunnyvale, CA

55 Years of Data

Avg High
60°F
Avg Low
42°F
Warmest
2025
62°F avg
Coldest
2008
42°F avg

About This Date

December 17th in Sunnyvale, CA typically brings mild winter weather, with average highs around 60°F and lows near 42°F. Over 55 years of records, the warmest December 17th was in 2025 (62°F average), while the coldest was 2008 (42°F) — a 20°F range across recorded history. Rain or other precipitation has occurred on about 33% of December 17th dates historically, with the wettest December 17th recording 2.24" of rain. Temperatures on this date have remained relatively stable over the past several decades.

Temperatures on this date have remained relatively stable over the past several decades.

Planning for December 17th in Sunnyvale, CA? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.

YearHighLowAvgPrecipSnow
2025warmest72°52°62°
202461°46°53°
202362°47°54°0.43"
202259°36°47°
202156°37°46°
202057°45°51°0.43"
201961°40°50°
201861°47°54°0.69"
201764°45°54°
201652°35°43°
201558°37°47°
201458°48°53°0.41"
201361°41°51°
201258°48°53°0.33"
201165°39°52°
201059°48°54°0.84"
200961°48°54°0.03"
2008coldest51°34°42°
200757°48°53°0.25"
200653°35°44°
200558°42°50°0.84"
200463°38°50°
200359°38°48°
200254°44°49°1.07"
200159°48°54°0.25"
200063°41°52°
199960°37°49°
199870°44°57°
199760°47°53°
199664°40°52°
199556°38°47°
199459°39°49°
199352°39°45°
199257°43°50°0.53"
199160°43°51°
199062°39°51°
198955°38°46°
198855°44°50°
198757°43°50°
198667°42°54°
198563°37°50°
198454°36°45°
198359°50°55°0.2"
198260°46°53°0.03"
198161°42°51°
198065°44°54°
197960°39°50°
197857°45°51°0.3"
197759°43°51°2.24"
197664°35°50°
197567°39°53°
197462°46°54°
197360°48°54°0.05"
197261°46°53°0.18"
197155°34°44°
55 years of data from MOFFETT FED AIRFIELD

Sunnyvale, CA Temperature Range by Month

Average monthly highs and lows. The shaded band shows the typical daily temperature range.

30°40°50°60°70°80°90°JFMAMJJASOND
Avg high Avg low

Sunnyvale, CA Monthly Precipitation

Average rainfall per month, in inches.

0"3.3"6.5"JFMAMJJASOND
Rain (in)

Sunnyvale, CA Daily Temperature Calendar

Average daily high temperature for every day of the year. Each cell is the climatological mean for that calendar day across 55 years of NOAA data.

151015202531JanFebMarAprMayJunJulAugSepOctNovDec
Cooler
Hotter
20°40°60°80°100°

Best Time to Visit Sunnyvale, CA

Most pleasant months in Sunnyvale, CA: July, August.

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Pleasant (65-82°F, ≤2.5" rain) Mild Less ideal

Browse Weather History

Weather data provided by NOAA Climate Data Online. Not for critical planning.

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