4 Billion Years On

Shifting Seasons

Climate change shows up in the calendar - spring arrives earlier and autumn lingers longer…

Climate change shows up in the calendar. Spring now arrives up to three weeks earlier across temperate regions; autumn lingers longer, more so toward the poles. Year-by-year links between seasonal timing and global temperature across 28 countries, a latitude chart from the Arctic to the Southern Ocean, a map of every monitored region, Kyoto's 1,200-year cherry-blossom record and the US growing season since 1895 - different data, different continents, the same story. Choose a place to see how its own seasons have shifted.

Key Facts

Earlier Springs
-9.5days
Mean across 130 temperate regions (125 earlier)
Later Autumns
+8.4days
Mean across 130 temperate regions (130 later)
Kyoto Blossom
−10.7days
Recent 30-yr mean vs pre-1850 (earlier)
NH Spring Snow
-8.7pp
Spring lost vs 1967-1976; latest Sep 2026: -3.9%
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Shifting Seasons Worldwide

Baseline (dashed) vs now (coloured). Of 234 countries, US states and UK regions, 125/130 have earlier springs, 130/130 later autumns; wet seasons are longer in 29 tropical/arid regions and shorter in 42.

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The Global Picture

How Seasons Have Shifted

Each region's first 30 years on record against its latest 10 - when monthly temperatures cross the baseline annual mean, revealing earlier springs, later autumns and shifting wet seasons.

World Map

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Biggest Warm-Season Shifts - Köppen C + D

Spring / autumn crossings are only meaningful where the climate has a genuine winter, i.e. Köppen temperate (C) or continental (D) groups. Tropical (A) and arid (B) regions are ranked by wet-season metrics below.

Spring Advancing Fastest
  1. 1Iceland-26.5 d
  2. 2Mexico-21.2 d
  3. 3New Zealand-21.1 d
  4. 4Chile-20.9 d
  5. 5Israel-15.9 d
  6. 6Lebanon-15.7 d
  7. 7Turkey-15.7 d
  8. 8Northern Ireland-15.7 d
Autumn Extending Latest
  1. 1Myanmar+25.5 d
  2. 2New Zealand+22.5 d
  3. 3Malawi+20.4 d
  4. 4Iceland+20.0 d
  5. 5Mexico+17.6 d
  6. 6Norway+17.5 d
  7. 7Greenland+15.6 d
  8. 8England SE & Central South+15.0 d
Warm Season Gaining Most Months
  1. 1Rwanda+6.83 mo
  2. 2Peru+4.77 mo
  3. 3Bolivia+1.90 mo
  4. 4Iceland+1.83 mo
  5. 5New Zealand+1.37 mo
  6. 6Lesotho+1.27 mo
  7. 7Greenland+1.17 mo
  8. 8Alaska+1.17 mo

Biggest Wet-Season Shifts - Köppen A + B

For tropical (A) and arid (B) climates the rains define the year. Onset (25% of annual rain) and end (75%) shifts together describe whether the wet window is moving, lengthening or shrinking; annual-total change is the signal that matters most for agriculture.

Biggest Wet-Season Onset Shift
  1. 1Tajikistan+362 d
  2. 2Turkmenistan-357 d
  3. 3East Timor+356 d
  4. 4United Arab Emirates-346 d
  5. 5Oman-125 d
  6. 6Algeria-35 d
  7. 7Pakistan+25 d
  8. 8Tunisia-19 d
Biggest Wet-Season End Shift
  1. 1New Caledonia-28 d
  2. 2Qatar+26 d
  3. 3Djibouti+23 d
  4. 4United Arab Emirates+22 d
  5. 5Nevada-20 d
  6. 6Saudi Arabia+20 d
  7. 7Estonia+16 d
  8. 8Afghanistan+14 d
Biggest Annual-Precipitation Change
  1. 1Jordan-65.1%
  2. 2Libya-63.4%
  3. 3Egypt-63.0%
  4. 4Syria-46.6%
  5. 5Morocco-41.9%
  6. 6Mauritania-39.7%
  7. 7Saudi Arabia-36.7%
  8. 8Algeria-33.9%

Method: first 30 complete years on record against the last 10. Warm season = months above the baseline annual mean; spring and autumn = the days the monthly climatology crosses it; wet-season onset = the day 25% of the baseline annual rain has fallen. Rain: GPCC (DWD), with CRU TS (World Bank CCKP) where GPCC has no cover; snow: GPCC, 1982–present. Köppen zones: Peel et al. 2007.

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The Warming Fingerprint

Do the Seasons Track Global Temperature?

Year by year, US spring arrival tracks global temperature almost perfectly - not random variation, and not El Niño. The clearest window is the US EPA's nationwide frost dates, averaged across thousands of stations every year since 1895; 96% of countries show the same direction of change.

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Seasons Shift at Every Latitude

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Historical Records

Kyoto - 1,200 Years of Cherry Blossom

Court diaries, monastery records and weather observations have logged Kyoto's cherry full bloom (満開, mankai) almost every year since 812 CE - the longest biological climate record on Earth.

Recent 30-yr Mean
5 Apr
full-bloom date
Pre-1850 Mean
15 Apr
the long-term norm
Shift
−10.7days
earlier than pre-1850
Earliest on Record
26 Mar
2021 - in 1,200 years
Full-bloom date, each year30-year rolling meanPre-1850 mean (15 Apr)

Earlier in the year is higher up the chart.

Source: Aono & Kazui (2008) and Aono & Saito (2010), via NOAA NCEI Paleoclimatology; recent decade extended from JMA Kyoto sakura observation records.

4byo Climate Helix 4byo Climate Symphony

Northern Hemisphere Snow Cover

Satellites have mapped Northern Hemisphere snow cover weekly since 1966. Winter extent has held up, but spring snow is collapsing - melting out weeks earlier and exposing darker land that absorbs more sunlight.

Spring, Last 10 Yrs
−4.0%
vs the 1981–2010 average (Mar–May)
Winter, Last 10 Yrs
−0.6%
vs 1981–2010 (Dec–Feb) - holding up
Spring, Since the 1960s
−8.7pts
lost since 1967–1976, on the same scale

Spring vs Winter Snow Cover

Spring (Mar–May), 10-year meanSpring, each yearWinter (Dec–Feb), 10-year meanWinter, each year

Anomaly = % difference from the 1981–2010 monthly mean, averaged over the three months of each season.

Last Two Years, Month by Month

Below the 1981–2010 normalAbove normal

Updates monthly from Rutgers Global Snow Lab.

Source: Rutgers University Global Snow Lab (NOAA NESDIS satellite analyses). Climatology baseline 1981–2010.

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United States

Spring Arrival Across the US - Live

The USA National Phenology Network's daily model: how many days early or late spring leaf-out and first bloom are arriving, against 1991–2020. Updated daily, Feb–May.

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The US Growing Season

Since 1895 the contiguous-US growing season - last spring frost to first autumn frost - has lengthened sharply, most in the West, where earlier springs and later autumns compound.

Recent 10-yr Avg
+11.7days
vs 1895-2020 mean (2011–2020)
Net Lengthening
+17.2days
recent 10y minus first 30y (1895–1924)

CONUS Growing-Season Length, 1895–2020

Longer than the 1895–2020 meanShorter

The direction of change is clear from around the 1980s onward.

Source: EPA Climate Change Indicators: Length of Growing Season. Underlying data: Kunkel (2021). Coverage: 1895–2020 (Contiguous 48 states). The EPA suspended updates to this indicator after April 2021, so the series is authoritative historically but ends in 2020. We plan to supplement with current-year figures from NOAA's xmACIS in a follow-up.

FAQs

FAQs

What does the shifting seasons page show?

How the timing and length of meteorological seasons have changed under climate change - when spring now begins, how long summer lasts, when winter snow cover starts and ends, and how these shifts vary by hemisphere and by country. The live charts and the country comparison panel above carry the current values.

Can I see how the seasons have shifted where I live?

Yes - use the picker at the top of the page to choose a continent, country, US climate region, US state or UK region, by search, list or map. Its own seasons card then loads below: when spring and autumn now arrive compared with its first 30 years on record, how much longer the warm (or wet) season has become, and month-by-month temperature, rainfall and, where recorded, snow and sunshine. The places named in the leaderboards further down open the same way.

How are season-shift indicators measured?

Spring onset uses the USA-NPN Spring Leaf and Bloom Index (USA) and equivalent phenological and temperature-threshold indicators elsewhere. Growing-season length uses the first and last date with daily mean temperature above a region-appropriate threshold. Snow cover uses the Northern Hemisphere snow-cover extent series from Rutgers University Global Snow Lab.

Where does the seasonal data come from?

USA: NOAA NCEI nClimDiv, USA-NPN, EPA Climate Change Indicators. Northern-Hemisphere snow: Rutgers Global Snow Lab. Country-level seasonal anomalies: Berkeley Earth, Copernicus C3S / ERA5. UK seasonal anomalies: Met Office HadUK-Grid.

What baseline is used?

Anomalies are calculated against the 1991-2020 climate normal where available (WMO standard). Some indicators (snow cover, US growing season) use longer reference periods set by the source agency; the baseline is labelled on each chart.

Are summers getting longer?

Yes. The growing season - the run of days with mean temperature above a region-appropriate threshold - has lengthened across most of the Northern Hemisphere since 1970, with the sharpest gains in the contiguous United States and northern Europe. The exact change for any one country, US state or UK region is shown live on this page in the season-length chart and the country comparison panel above; we do not bake numbers into this FAQ because they refresh annually.

When does spring arrive now compared with the past?

Spring is arriving earlier across most of the temperate Northern Hemisphere. The USA-NPN Spring Leaf and Bloom Index (USA), Met Office HadUK-Grid temperature thresholds (UK) and Berkeley Earth / Copernicus ERA5 (rest of the world) all show first-leaf and first-bloom dates trending earlier by roughly one to three weeks since 1980, depending on the region. Pick a country in the country comparison panel above to see the live spring-onset anomaly.

Why are seasonal shifts a useful climate indicator?

Annual mean temperature can mask big within-year changes. Earlier spring leaf-out, longer frost-free windows, later first-snow dates and shorter snow-cover seasons all change the environment for crops, pests, pollinators and water supply long before the headline temperature anomaly looks alarming. They are also independent of the choice of climate baseline, which makes them a good cross-check on the temperature record.

What do the markers at each end of the seasonal bars show?

Each end of a bar has a before-and-after marker. The hollow grey circle is the average date in the baseline period (the first decades on record), the solid coloured circle is the average date in the most recent decades, and the line between them is the shift - labelled in days, minus for earlier and plus for later. Tap or hover a marker for the decade-by-decade dates (shown as dots on the bar), each with how warm the world was in that decade, which shows the warmest recent decades are also the ones with the most shifted seasons.

Which countries show a shifting wet season?

The wet-season shift chart appears for countries where a distinct rainy season can be identified from the temperature and precipitation record - primarily tropical and subtropical countries across South and Southeast Asia, sub-Saharan Africa, Central America and northern Australia. Temperate countries with year-round rainfall distribution (most of Europe, for example) show the warm-season chart instead. The data source is Copernicus ERA5 via Berkeley Earth country-level aggregates.

How often is this page updated?

Annual indicators (growing-season length, snow-season length) refresh once a year as the source agencies publish them. Monthly indicators refresh on the same monthly cadence as the rest of the site, typically in the first half of each month.