| Year | SW Monsoon Rainfall (mm) | % of LPA | IMD Category | Departure from LPA | ENSO Condition | ★ UP & Delhi Peak Month | Approx. Rainfall UP (mm) | Approx. Rainfall Delhi (mm) | Notable Event / Remark |
|---|
July & August: The Twin Monsoon Peaks of North India
According to IMD data, Uttar Pradesh and Delhi consistently receive their highest rainfall in July and August each year. Delhi's climatological normal shows 210.6 mm in July and 247.7 mm in August — making August the single wettest calendar month on average, though July can surpass it in strong monsoon years. In 2021, Delhi received an extraordinary 507.1 mm in July alone — 141% above normal, the second-highest on record. In 2024, August saw 22 consecutive rainy days, the highest since 2012, with Delhi recording 278.4 mm. For Uttar Pradesh (East & West UP subdivisions), July is typically the peak month, carrying the maximum number of rainy days — 15 to 20 days on average.
Delhi — Month-wise Normal Rainfall (IMD)
- January: 21.1 mm
- February: 18.7 mm
- March: 15.9 mm
- April: 7.7 mm
- May: 21.5 mm
- June: 74.1 mm (Pre-monsoon onset)
- July: 210.6 mm ← Peak rainy days
- August: 247.7 mm ← Highest volume
- September: 126.8 mm
- October: 31.0 mm
- November: 5.6 mm
- December: 11.3 mm
Uttar Pradesh — Key Monsoon Facts (IMD)
- UP is part of the "Indo-Gangetic Plain" met sub-division
- Annual normal rainfall: ~900 mm (W. UP) to ~1000 mm (E. UP)
- July is the peak month for number of rainy days (~18–22 days)
- August follows closely — highest volume month in many years
- Monsoon arrives in UP: ~18–25 June (normal onset)
- Monsoon withdraws: ~5–15 October
- 2002 drought hit UP severely: 25% below normal
- 2013 & 2019 saw record excess rainfall in eastern UP
- Climate shift: July declining, September wetter — per IMD 2024 analysis
Decadal Patterns
2000–2009: Two major droughts (2002, 2004, 2009). 2002 was India's worst drought in decades at 81% of LPA.
2010–2019: Generally average but with strong droughts in 2014–2015 (back-to-back deficient years). 2019 marked a strong recovery at 110% LPA.
2020–2024: More active monsoons overall. 2020 recorded excess rainfall. 2023 was slightly below-normal. 2024 rebounded to 108% LPA with record extreme rainfall events.
Climate Change Signals (IMD & MoES)
Extreme events rising: 2024 saw 2,632 very-heavy and 473 extremely-heavy rainfall events — a 5-year record per IMD.
Seasonal shift: July, once the peak monsoon month nationally, now shows declining rainfall. September is becoming wetter.
IGP decline: The Indo-Gangetic Plain (covering UP, Delhi, Haryana) shows a statistically significant declining trend in monsoon rainfall over the past decade (CEEW, 2022–23 study on IMD data).
Uneven distribution: More frequent extremes — floods in some districts, drought in neighbouring ones.
Notable Drought Years (Deficient Monsoon)
- 2002: 81% of LPA — worst in 25 years; 29 of 36 sub-divisions deficient
- 2004: 87% of LPA — widespread moderate drought
- 2009: 78% of LPA — second worst after 2002; severe food impact
- 2014: 88% of LPA — below normal; 12 sub-divisions deficient
- 2015: 86% of LPA — El Niño year; 16 sub-divisions deficient (worst in decade)
- 2023: 94% of LPA — officially classified as below-normal/near-drought
Notable Flood / Excess Monsoon Years
- 2005: 99% LPA but extreme events in Mumbai (July 26 — 944 mm in 24 hrs)
- 2007: 106% LPA — major floods Bihar, UP, Assam
- 2013: 106% LPA — Uttarakhand flash flood disaster (June)
- 2019: 110% LPA — excess; major floods Kerala, Maharashtra, Assam
- 2020: 110% LPA — excess; widespread flooding across India
- 2022: 106% LPA — above normal; UP and Assam severely flooded
- 2024: 108% LPA — above normal; record extreme rain events
Official Government Sources Used
- India Meteorological Department (IMD) — mausam.imd.gov.in & imdpune.gov.in — Primary source for all rainfall statistics, monsoon season reports, LPA values, and sub-divisional data
- Ministry of Earth Sciences (MoES), GoI — Annual Rainfall Statistics publications (Rainfall Statistics of India — 2024 and preceding years)
- Open Government Data Platform India (OGD) — data.gov.in — Month-wise, subdivision-wise rainfall data under NDSAP policy
- Reserve Bank of India (RBI) — Handbook of Statistics on States — Year & IMD sub-division-wise actual annual rainfall (1901–2024)
- Ministry of Statistics & PI (MoSPI) — Statistical Year Book of India, Rainfall Chapter
- NITI Aayog / ICED Platform — iced.niti.gov.in — Climate variability rainfall data
Note: UP & Delhi monthly rainfall figures are approximate based on IMD climatological normals and published sub-divisional departure data. Exact rainy-day counts by year require direct access to IMD station-level daily data archives (CDSP: cdsp.imdpune.gov.in). All data compiled is sourced from Government of India official portals only, in compliance with the National Data Sharing and Accessibility Policy (NDSAP).