Preparing for El Niño 2026-27 October Edition

THE WINDY EL NIÑO — October Update: a strategic outlook report for New Zealand farmers, growers and rural businesses

The 2026/27 El Niño is now the strongest on record on the measure that combines ocean and atmosphere, and every forecast model peaks it in December above anything previously recorded. For New Zealand it is not a drought-and-heat event. It is a wind event: stronger westerlies from November to March, wet in the west and south, dry and high-evaporation north and east of the ranges, with the pinch for the East Coast and the Canterbury plains arriving in February–March.

This is the final issue of the report that has tracked the event since May. It is written for farmers, growers and rural decision-makers, in plain language, and it is built around one question: what do I need to decide, and when?

Inside:

• What has changed since September — stated first. The November lull came early, in October; November is now the month the westerlies return in force, and the month to act in.
• The season in five phases, November to April, from the nine international forecast models run at the start of October — including the South Island summer temperature question, now decided by the ranges.
• What history says. Reasoned month-by-month comparisons with 1877/78, 1982/83, 1997/98 and 2015/16 — what each did to New Zealand farming, which one this season most resembles, and what the farmers who came through them well did differently.
• All thirteen regions, each with a month-by-month table, the pattern, what has changed, spring and summer decision points, and the single trigger to watch — plus a separate Fiordland hydro outlook.
• Sector guidance for dairy, sheep and beef, arable, horticulture, viticulture, forestry and others, with the costs now quantified.
• The national decision calendar, the marker points that should make you change plan, and a one-page check for telling a real mid-summer break from a false one.
• Three scenarios with honest weights, and a full list of official and industry resources, every one verified in October.

50 pages, PDF, with plain-language operational framing throughout. Written for rural decision-makers, not meteorologists.

Why it matters now

With November and December looking relentlessly westerly, the low-cost preparation window is closing fast. Every comparison year says the same thing: the operators who moved store stock early sold into a working market, and those who waited until December sold into a queue. Feed contracts, destocking triggers, water and irrigation checks, fire plans, and conversations with your bank and processor are all cheaper and easier in the next few weeks than under summer pressure.

About Blue Skies

Tony Trewinnard has been producing seasonal climate forecasts for New Zealand agricultural, horticultural and energy-sector clients for over 35 years. Blue Skies Weather specialises in translating international climate model guidance into the operational planning decisions rural businesses actually face.

Looking for ongoing guidance?

This report is one product in the Blue Skies range. The Blue Skies Outlook subscription on Substack costs $395 a year. It includes this report, monthly seasonal outlooks, weekly six-week updates, and direct email access for sector- and catchment-specific questions through the 2026–27 season https://bswx.substack.com

Format: PDF, 50 pages, approximately 12 MB. Issued 16 October 2026. This is the final update for 2026.