Rain frequency and volume tell two different stories. Friday strikes most often. Sunday strikes hardest. Thursday is your only reliable escape.
Every weekend from June through August, 2023 through 2025. Color intensity maps to rain volume. The heavy ones leave a mark.
ERA5 reanalysis + NWS data across 38 NYC summers (1988–2025). Weekends and weekdays trade the lead year to year — but 2009 and 2011 stand out as the worst weekend summers on record.
The 1990s were definitively wetter on weekends. The 2000s flipped completely — weekdays dominated. The 2010s were a dead tie. Now the pattern is returning. No decade tells the same story.
Blue bars = weekends were rainier. Amber bars = weekdays were rainier. The 38-year record is nearly split: 18 years weekends won, 20 years weekdays won. But the swings are wild.
Not all summer months are equal. June tends to start drier. July brings the highest storm frequency. August dumps the most rain per day. The weekend bias varies significantly by month.
It's not just NYC folklore. There's a peer-reviewed explanation — and the physics behind it is as grimy as a rush-hour subway platform.
38 years of data produce some jaw-dropping outliers. From the driest weekend summer on record to the most lopsided single-year swing ever measured.
NYC summers don't just rain on weekends randomly — they cluster. 2023 opened with nine straight weekends of measurable rain. Historically, weekdays held a 6-year stranglehold from 2003 to 2008.
Hit play to watch the weekend vs weekday rain race animate year by year from 1988. See the lead change hands, the 2009 spike, and the recent comeback.
Select any two years from 1988 to 2025 and compare every metric side by side. How does 2009 (the worst) stack up against 2014 (the best)?
Each cell is one summer. Color shows how much rainier weekends were vs weekdays — deep blue means weekends got hammered, amber means weekdays were the victims.
A GitHub-style contribution graph for summer rain. Each square is one day, colored by precipitation. The clusters make the pattern visceral — weekends light up blue in waves.
Linear regression across 38 summers shows weekend rain rate increasing by +0.08% per year — about +3% per decade. The trend is real but modest (R² = 0.008). Climate change is intensifying precipitation events, not just the frequency.
Cerveny & Balling (1998, Nature) identified the effect in coastal cities from D.C. to Boston. Atlanta shows it strongest. Chicago barely. Los Angeles: not at all. The aerosol-seeding mechanism requires both dense urban activity and coastal moisture.
When 71% of NYC summer weekends get rained on, the economic ripple is enormous. Outdoor dining, park visits, events, and tourism all take the hit.
NWS sky cover and temperature records show weekends running cloudier and cooler — consistent with precipitation suppressing daytime highs. Thursday stays clearest and warmest.
NWS Central Park Station (USW00094728) · June–August 2023–2025 daily records · 39–40 observations per day of week.