US West Climate – March 2026 Update
Top States: California and Nevada
This month in numbers
The US West climate region experienced a significantly warm month, with a 1-month anomaly of +7.09°C compared to the 1961–1990 average. The 3-month anomaly stands at +4.58°C, and the 12-month anomaly is +2.90°C. This places the US West as the warmest region globally for the latest month, with all of the top 10 warmest regions being US states.
Hottest & coolest US states
Within the US West region, Nevada climate page was exceptionally warm, recording a +7.18°C anomaly. California climate page also saw unusually high temperatures, with an anomaly of +7.01°C. In stark contrast, Alaska was the coolest US state, with a 1-month anomaly of -5.93°C.
What's driving change?
The current ENSO state is Neutral, with an anomaly of +0.11°C vs 1991–2020 for February-April 2026. The probability for Neutral conditions remains highest for April-June 2026 at 80%, shifting to a likely El Niño phase by May-July 2026 with a 61% probability. ENSO tracker This past March, the western US experienced an unusually early and significant heatwave, driven by a strong, slow-moving high-pressure system, commonly known as a heat dome. This event led to over 1,500 daily record high temperatures being set across the US between March 16 and 23, with 660 of those being all-time March heat records. The heatwave was intensified by a 5,000-mile-long marine heat wave in the Pacific Ocean. This early burst of warmth is expected to have lasting impacts into the summer months, increasing risks for ecosystem stress and early wildfires. The warming drivers at play include and , as many areas in the West are also grappling with drought conditions.
Looking ahead
The NOAA Climate Prediction Center forecasts above-average temperatures for much of the lower-48 states in the 8-14 day period.
Generated by Gemini from climate data and web sources
Climate Map – USA
Source: NOAA Climate at a Glance — US states & climate regions (tavg, pcp). Anomalies are vs the 1961–1990 baseline (temperature) or 1991–2020 (rainfall). See methodology.
Temperature – Average
US West – Monthly Temperature – All Years
Each line represents one year of monthly temperature in °C.
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
Shifting Seasons
Warm / cold seasonsHow spring and autumn have shifted in US West. Spring is defined as the date monthly temperatures first rise above the long-term annual mean (12.3°C, from 1950–1979); autumn is the date they fall back below it. Temperature swings 20.4°C peak-to-peak across the year - a classic four-seasons rhythm.
Baseline vs recent monthly temperature climatology. Biggest warming: Jun (+2.0°C).
NOAA Climate at a Glance — regional tavg.
Rainfall & Rain Days – Totals
Member States (2)
Hottest & Coolest in US West this Month
1-month anomaly vs 1961–1990 across the 2 members we cover. Click a name to open its profile.
Warmest
- 1.☀️California+1.33°C
- 2.🇺🇸Nevada+1.17°C
Coolest
- 1.🇺🇸Nevada+1.17°C
- 2.☀️California+1.33°C
Data Sources
- NOAA Climate at a Glance — Regional time series · NOAA code 109 · Open at NOAA
- Two-baseline model — comparison baseline 1961–1990; native baseline 1901–2000. Methodology →
Data Sources
Data Sources for US West
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.
FAQs
FAQs
How is the climate in US West changing?
US West 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 trend rate is shown as °C per decade in the headline panel; you can also see the warmest and coolest years on file.
Where does the climate data for US West come from?
Climate data for US West 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 West climate data cover?
The US West climate profile covers California, Nevada and surrounding areas. NOAA West - CA, NV
How often is the US West climate update refreshed?
The US West 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.