US Ohio Valley Climate – May 2026 Update
Top States: Ohio, Illinois, Missouri, Indiana, and Tennessee
This month in numbers
The US Ohio Valley experienced a near-average May, with a 1-month temperature anomaly of -0.03°C compared to the 1961–1990 average. This follows a significantly warmer 3-month period, which saw an anomaly of +2.98°C, and a 12-month rolling anomaly of +1.73°C. Globally, the latest month saw a striking concentration of warmth in other regions, with 10 of the top 10 warmest anomalies being countries outside the US.
Hottest & coolest US states
Within the US Tennesseed border-teal-300/60 text-teal-300 hover:text-teal-200 hover:border-teal-20US Kentucky>US Ohio Valley region, Tennessee (US Tennessee) was the warmest state in May, recording an anomaly of +0.56°C. Kentucky (US Kentucky) also experienced above-average temperatures at +0.22°C. In contrast, Ohio () was notably cooler, with a 1-month anomaly of -0.71°C, ranking as the coolest state in the group. Indiana (US Indiana) and West Virginia (US West Virginia) also saw below-average temperatures.
What's driving change?
The current ENSO state is Neutral, with an anomaly of +0.48°C for March-May 2026. However, a strong El Niño is highly likely to develop and persist through the Northern Hemisphere winter, with a 99% chance for June-August and 100% for August-September. While El Niño's influence on summer weather in the Midwest is often limited, it typically brings a warmer and drier winter to Ohio and much of the Midwest. May saw above-average precipitation across portions of the Ohio Valley, which helped to ease drought concerns heading into summer. Despite this, some areas of West Virginia remained in moderate to severe drought at the end of May.
Looking ahead
El Niño is expected to strengthen through the autumn, potentially shaping US weather through harvest and into winter, with typical impacts including drier conditions in the Ohio Valley.
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 Ohio Valley this Month
1-month anomaly vs 1961–1990 across the 7 members we cover. Click a name to open its profile.
Warmest
- 1.🇺🇸Tennessee+0.56°C
- 2.🇺🇸Kentucky+0.22°C
- 3.🇺🇸Missouri+0.08°C
- 4.🇺🇸Illinois+0.06°C
- 5.🇺🇸West Virginia-0.28°C
Coolest
- 1.🇺🇸Ohio-0.71°C
- 2.🇺🇸Indiana-0.46°C
- 3.🇺🇸West Virginia-0.28°C
- 4.🇺🇸Illinois+0.06°C
- 5.🇺🇸Missouri+0.08°C
Member States
Year-on-Year Trends
The 4byo Climate Helix – US Ohio Valley
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
US Ohio Valley – Monthly Temperature – All Years
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
Records – US Ohio Valley
NOAA Climate at a Glance — regional tavg / pcp (monthly absolutes).
Shifting Seasons
Warm / cold seasonsHow spring and autumn have shifted in US Ohio Valley. Spring is defined as the date monthly temperatures first rise above the long-term annual mean (11.7°C, from 1950–1979); autumn is the date they fall back below it. Temperature swings 25.9°C peak-to-peak across the year - a classic four-seasons rhythm.
Baseline vs recent monthly temperature climatology. Biggest warming: Mar (+2.5°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
Loading ENSO tracker…
Emissions & Energy
Explore
Explore Climate Data
Data Sources
Data Sources for US Ohio Valley
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 Ohio Valley changing?
US Ohio Valley 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 Ohio Valley come from?
Climate data for US Ohio Valley 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 Ohio Valley climate data cover?
The US Ohio Valley climate profile covers Ohio, Illinois, Missouri, Indiana and surrounding areas. NOAA Ohio Valley - IL, IN, KY, MO, OH, TN, WV
How often is the US Ohio Valley climate update refreshed?
The US Ohio Valley 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.