US Northwest Climate – July 2026 Update
Top States: Washington, Oregon, and Idaho
Summary
The US Northwest experienced an exceptionally hot period, running 2.41°C above the 1961-1990 average as persistent dry conditions fuelled an unprecedented wildfire season. Record-breaking blazes scoured millions of acres, destroying hundreds of homes around Spokane and draping the region in toxic smoke plumes. The warmth coincides with a moderate El Niño in the Pacific Ocean, which continues to intensify and holds a 93% probability of reaching Very Strong strength in Sep-Nov. With background warming and dry terrain amplifying the heat, seasonal outlooks suggest above-average temperatures will persist across the region in the coming months.
This month in numbers
The region logged a 1-month temperature anomaly of +2.41°C above the 1961-1990 baseline, while the 3-month figure reached +1.94°C and the 12-month rolling anomaly stood at +2.45°C. Over the past year, the Northwest has formed part of a broader continental pattern where 7 of the top 10 warmest territories globally are US states, including Idaho in 10th position with a 12-month anomaly of +2.79°C.
Hottest & coolest US states
All three states in the region ran significantly warmer than their long-term averages. Idaho (US Idaho) led the group with a striking 1-month anomaly of +3.12°C, while Oregon (US Oregon) followed at +2.15°C and Washington (US Washington) recorded +1.88°C above average.
What's driving change?
The prevailing warmth is shaped by an active Pacific climate pattern, with the tropical Pacific currently in a moderate El Niño state featuring a Relative Niño Index anomaly of +0.98°C at ENSO. Official forecasts indicate a 93% probability of the event reaching Very Strong intensity in Sep-Nov, which historically brings mild winter weather and lighter mountain snowpack to the Northwest via the Pacific-North American Pattern. Locally, and have intensified surface heating, creating tinderbox conditions. All of US Northwest's 3 wildfires this year have happened in the past month, with major blazes in Washington and Oregon tracked at Extreme Weather tracker.
Looking ahead
Seasonal outlooks from the Climate Prediction Center indicate a strong likelihood of above-normal temperatures and below-average precipitation continuing across the US Northwest over the next 1-3 months as El Niño strengthens.
Generated by Gemini from climate data and web sources
At a Glance
Temperature – Average
Climate Map – USUnited States
Source: NOAA Climate at a Glance — US states & climate regions (tavg, pcp), plus GPCC (Snow, water-equivalent). Anomalies are vs the 1961–1990 baseline. See methodology.
Long-Term Trends
Combined Timeline – US Northwest
Precipitation, Sunshine, Frost and Snow are converted to standard deviations from their own average so they can share an axis with Temperature.
NOAA Climate at a Glance - regional tavg / pcp
Heatwave Days – US Northwest
Warm Spell Duration Index (WSDI) - days in a 6+ day run above the local 90th-percentile temperature for that time of year.
Data: World Bank Climate Change Knowledge Portal (ERA5-derived), aggregated by 4BYO across member states. Refreshed roughly 1-2x/year, ~7-8 months behind present.
Hottest & Coolest in US Northwest this Month
1-month anomaly vs 1961–1990 across the 3 members we cover. Click a name to open its profile.
Warmest
- 1.🇺🇸Idaho+3.12°C
- 2.🇺🇸Oregon+2.15°C
- 3.🇺🇸Washington+1.88°C
Coolest
- 1.🇺🇸Washington+1.88°C
- 2.🇺🇸Oregon+2.15°C
- 3.🇺🇸Idaho+3.12°C
Year-on-Year Trends
The 4byo Climate Helix – US Northwest
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
Monthly Temperature – US Northwest
Background lines show the last 40 years (plus the record year and its opposite, wherever they fall).
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
Records – US Northwest
NOAA Climate at a Glance - regional tavg / pcp - Anomalies vs 1901-2000 mean
Shifting Seasons
Warm / cold seasonsHow spring and autumn have shifted in US Northwest. Spring is defined as the date monthly temperatures first rise above the long-term annual mean (7.3°C, from 1950–1979); autumn is the date they fall back below it. Temperature swings 21.0°C peak-to-peak across the year - a classic four-seasons rhythm.
Baseline vs recent monthly temperature climatology. Biggest warming: Aug (+1.9°C).
NOAA Climate at a Glance — regional tavg. Baseline: first 30 yrs on record. Recent: last 10 yrs on record.
Climate Systems
Loading ENSO tracker…
Emissions & Energy
Explore
Explore Climate Data
Data Sources
Data Sources for US Northwest
Every figure on this page is sourced from official, openly published climate datasets. Anomalies are calculated against the 1961–1990 baseline (temperature) and 1991–2020 (rainfall, sunshine, frost) - see the Methodology & Sources page for the complete dataset list and update calendar.
US 9-region temperature and precipitation series (1895–present).
US state-level CO₂ emissions and electricity generation mix by fuel source. Energy Information Administration.
Frost Days and Heatwave Days (Warm Spell Duration Index), ERA5-derived. World Bank Climate Change Knowledge Portal.
Monthly snow water-equivalent, Global Precipitation Climatology Centre (DWD).
FAQs
FAQs
How is the climate in US Northwest changing?
US Northwest is warming in line with the rest of the world. The page above shows the latest monthly temperature anomaly versus the 1961-1990 baseline, the long-term annual trend, and the region's rank in the historical record. The headline panel also shows the long-term trend rate per decade and the warmest and coolest years on file.
Where does the climate data for US Northwest come from?
Climate data for US Northwest comes from authoritative climate datasets including national meteorological services and peer-reviewed reanalyses, refreshed every month, when the upstream temperature and rainfall data are refreshed.
What is the climate baseline used on this page?
Anomalies on this page are calculated against the 1961-1990 climatological baseline, which is the standard reference period used by the Met Office, NOAA, IPCC and most national climate services. Some panels also show the source-native 1901-2000 (NOAA) or 1991-2020 (WMO) baselines for verification. See Methodology & Sources for the full reference.
Which areas does the US Northwest climate data cover?
The US Northwest climate profile covers Washington, Oregon, Idaho and surrounding areas. NOAA Northwest - ID, OR, WA
How often is the US Northwest climate update refreshed?
The US Northwest climate update is refreshed monthly, typically a few days after the previous month closes and the upstream provider (Met Office HadUK-Grid, NOAA Climate at a Glance, Copernicus ERA5 or the Global Carbon Project) publishes its update. See the Climate Rankings for cross-region comparisons.
What counts as a Heatwave Day on the US Northwest climate page?
Heatwave Days use the Warm Spell Duration Index (WSDI) - the WMO/ETCCDI-standard heatwave measure: days that are part of a run of 6 or more consecutive days above the local 90th-percentile temperature for that calendar day. The 90th-percentile threshold varies by time of year (a hot day in January is judged differently to one in July) but is fixed to the 1961-1990 baseline for every year shown - it does not shift as the climate warms, which is why Heatwave Days trend upward over time.
Does the US Northwest climate page include frost and snow data?
Yes. Frost Days (days with a minimum temperature below 0°C, World Bank CCKP) and snow water-equivalent (GPCC) are shown alongside temperature and precipitation, each measured against the 1961-1990 baseline where a like-for-like historical comparison is available.