Shared dry summers showed no clear change between England and Scotland in two 95-year periods from 1836 to 2025

We tested a change in shared dry summers in England and Scotland with Met Office rainfall records for 1836-2025. Dry means at or below each country and period 20th percentile of June-August totals. Each country had 19 dry summers in each 95-year period. Shared counts were ten in 1836-1930 and nine in 1931-2025. The shared fraction above an independent-country reference fell by 1.05 percentage points. The 95% five-year block interval was -5.89 to +6.32 points. Thresholds were re-estimated in each of 19,999 draws. All eight checks had intervals across zero. This gives no clear direction of change under these methods. It does not show equal risk or stable water supply. Country averages, early source quality, few tail events, period choice and block assumptions limit inference. Code, aggregate evidence, source hashes, an audit and a figure are included. Exact external records are needed for full recomputation and stay outside the signed package.

rainfall · shared dry summers · England · Scotland · spatial dependence · block bootstrap · null result