Gilliam County Climate
Gilliam County, Oregon
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
51.7°F
Annual Precip
11.7"
Annual Snowfall
15.4"
Extreme Heat Days
31
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
7b
Minimum winter temperature range for plant survival
2,695
Supports most vegetables & fruits
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Gilliam County
Climate Verdict
Gilliam County has a mild, with an average annual temperature of 51.7°F, arid conditions receiving just 11.7 inches of precipitation annually, occasional hot days — 31.1 per year above 90°F, light snow averaging 15.4 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are cold, with January averaging 34.1°F. summers are warm — July averages 72.3°F. The 38°F seasonal variation provides noticeable but manageable change. December is typically the coldest month and July the warmest.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for Gilliam County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
Gilliam County closely matches the Oregon statewide average temperature of 50.5°F, it is also noticeably drier, receiving 25.7 inches less precipitation than the state average.
Climate Profile
About Gilliam County Weather
A Warm and Very Arid Landscape
Gilliam County averages 51.7°F annually, placing it near the national median for temperature. Its 11.7 inches of annual precipitation, however, makes it one of the drier regions in the country.
Warmer but Much Drier than Oregon
The county is slightly warmer than the state average of 50.5°F. Conversely, it receives only a fraction of the state's average rainfall, seeing just 11.7 inches compared to 37.4 inches statewide.
A Warmer Pocket in Northern Oregon
Gilliam's average temperature of 51.7°F is higher than neighboring Jefferson County at 48.5°F. It shares a similar arid profile with other regional neighbors, maintaining very low annual precipitation.
Hot Summers and Light Snowfall
July is hot with an average of 72.3°F and 31 days of extreme heat exceeding 90°F. Winters are manageable, featuring a January average of 34.1°F and 15.4 inches of total annual snowfall.
Prioritize Cooling and Water Management
With 31 extreme heat days, efficient air conditioning is a necessity for residents. The extremely low rainfall of 11.7 inches suggests that xeriscaping is the most practical choice for outdoor spaces.
Frequently Asked Questions
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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.
Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.