US Northern Rockies & Plains Climate – May 2026 Update
Top States: Montana, Nebraska, North Dakota, South Dakota, and Wyoming
This month in numbers
The US Northern Rockies & Plains experienced a significantly warmer May, with a 1-month temperature anomaly of +1.00°C compared to the 1961–1990 average. The warming trend is even more pronounced over longer periods, with a 3-month anomaly of +2.05°C and a 12-month rolling anomaly of +2.53°C. Globally, the region's 1-month anomaly did not place it among the top 10 warmest, which were dominated by countries in Central and West Asia.
Hottest & coolest US states
Within the US Northern Rockies & Plains, Montana (US Montana) was notably warmer, recording a 1-month anomaly of +1.75°C. Wyoming (US Wyoming) also experienced above-average temperatures at +0.93°C, as did Nebraska (US Nebraska) at +0.68°C. While no states in the region were strikingly cool, South Dakota (US South Dakota) and North Dakota (US North Dakota) recorded the lowest anomalies in the group at +0.48°C and +0.52°C respectively.
What's driving change?
The current climate pattern is strongly influenced by an emerging El Niño, with the NOAA ONI for MAM 2026 showing a neutral state but a dominant 97% probability of El Niño for May-Jul 2026, increasing to 100% for Aug-Oct 2026 and Sep-Nov 2026. ENSO. This developing El Niño typically brings warmer and drier conditions to the Pacific Northwest and Western Canada during winter, which can lead to lower mountain snowpack and increased summer wildfire risk. Drought conditions persisted across much of the western interior, Rockies, and Plains in May, with some expansion in parts of the northern Plains. Despite some late-season snow in parts of Wyoming and Colorado in early May, which brought temporary relief, experts noted it was insufficient to offset the season's overall snow deficit. This ongoing drought, combined with the , where higher-latitude regions warm faster than the tropics, contributes to the observed temperature anomalies.
Looking ahead
Above-average temperatures are favoured across the western and northern U.S., including the Northern Rockies and Plains, for June, with drought expected to persist and expand across much of the Northwest and portions of the Northern Rockies and Plains..
Generated by Gemini from climate data and web sources
At a Glance
Temperature – Average
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.
Hottest & Coolest in US Northern Rockies & Plains this Month
1-month anomaly vs 1961–1990 across the 5 members we cover. Click a name to open its profile.
Warmest
- 1.🇺🇸Montana+1.75°C
- 2.🇺🇸Wyoming+0.93°C
- 3.🇺🇸Nebraska+0.68°C
- 4.🇺🇸North Dakota+0.52°C
- 5.🇺🇸South Dakota+0.48°C
Coolest
- 1.🇺🇸South Dakota+0.48°C
- 2.🇺🇸North Dakota+0.52°C
- 3.🇺🇸Nebraska+0.68°C
- 4.🇺🇸Wyoming+0.93°C
- 5.🇺🇸Montana+1.75°C
Member States
Year-on-Year Trends
The 4byo Climate Helix – US Northern Rockies & Plains
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
US Northern Rockies & Plains – Monthly Temperature – All Years
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
Records – US Northern Rockies & Plains
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
Shifting Seasons
Warm / cold seasonsHow spring and autumn have shifted in US Northern Rockies & Plains. Spring is defined as the date monthly temperatures first rise above the long-term annual mean (5.7°C, from 1950–1979); autumn is the date they fall back below it. Temperature swings 30.0°C peak-to-peak across the year - a classic four-seasons rhythm.
Baseline vs recent monthly temperature climatology. Biggest warming: Jan (+3.3°C).
NOAA Climate at a Glance — regional tavg. Baseline: first 30 yrs on record. Recent: last 10 yrs on record.
Rainfall & Rain Days – Totals
Climate Systems
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Emissions & Energy
Explore
Explore Climate Data
Data Sources
Data Sources for US Northern Rockies & Plains
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 Northern Rockies & Plains changing?
US Northern Rockies & Plains 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 Northern Rockies & Plains come from?
Climate data for US Northern Rockies & Plains 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 Northern Rockies & Plains climate data cover?
The US Northern Rockies & Plains climate profile covers Montana, Nebraska, North Dakota, South Dakota and surrounding areas. NOAA Northern Rockies and Plains - MT, NE, ND, SD, WY
How often is the US Northern Rockies & Plains climate update refreshed?
The US Northern Rockies & Plains 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.