The Indian Ocean Dipole has shifted to negative phase and a borderline La Nina is developing. The last time -IOD and La Nina were present during SEP/OCT was in 2022 when buckets of rain fell on the East/Southeast! Be aware of potential over-achieving rains in the East for spring 2025! The AI Graph Cast week 2-4 outlook reveals the upcoming wet pattern for East Australia.

The North Atlantic basin SSTA is +0.28C which is quite cool compared to other years this decade. The 1-year change is -0.53C which is very impressive. However, there are basins which are very warm and capable of contributing to over-achieving tropical cyclones and their intensity. The Gulf of Mexico is near record warm (+0.90C) which is steady during the past 2 weeks. The Caribbean Sea is also very warm and unchanged during the past 2 weeks.

The official U.S. population weight CDD for August 2025 from NOAA will be published in a few days. Climate Impact Company (CIC) projects 272 CDD for August which is cooler than the 30-year normal (290 CDD) and much cooler than the 10-year normal (332 CDD). The NOAA assessment is (more) likely cooler than the CIC estimate. The AUG-25 CDD total is 2nd coolest (for AUG) this century trailing only 2004 (254 CDD).

The strongest marine heat waves (MHW) on record in the West Pacific and in-between Japan and the Asia Coast extending to MHW’s NEP25A and NEP25B in the Northeast Pacific are well-correlated to the summer 2025 upper air pattern featuring a strong upper-level high-pressure ridge. Similarly, the MHW’s in the east/northeast portion of the North Atlantic are well-correlated to a semi-permanent upper-level high-pressure ridge dominating the west/south portion of Europe during summer 2025.