About Us
South Island Met Agency (SIMA) is an independent, private meteorological service run by two forecasters based in the South Island of New Zealand. We publish hand-written forecasts with a focus on high-impact weather: thunderstorms, snow, heavy rain and severe winds.
How we forecast
Every SIMA product is written by a forecaster rather than generated automatically. We compare guidance from multiple global and regional numerical weather prediction models with current surface observations, atmospheric soundings, satellite imagery and radar to form a view of how the weather will evolve. Where models disagree, we say so, and our risk categories reflect that uncertainty.
The town forecasts, synoptic briefing and sounding charts on the home page are generated from public model data provided by Open-Meteo and are intended as supporting tools alongside our forecaster-written products.
Our products and update schedule
SIMA publishes five forecast products, each with its own purpose and cadence.
- Significant Weather Outlook: a five-day outlook updated daily by 10:30pm NZT, or every two days during settled weather.
- Regional Weather Notice: issued when significant weather is likely for a region, and reissued until the event has passed.
- StormCast: issued when significant thunderstorm activity is expected within 48 hours.
- SnowCast: issued when snow is forecast below 1000 metres, with short-term and extended alpine outlooks.
- News: articles, seasonal outlooks and event reviews written by our forecasters.
Accuracy and corrections
Weather forecasting is inherently uncertain. We aim to be clear about confidence levels and to update products promptly when the picture changes. If you believe a forecast or article contains an error, please contact us and we will review and correct it where appropriate.
Funding and advertising
SIMA is funded by display advertising served through Google AdSense, by sponsor banners from local businesses, and by private forecasting services for organisations. Advertising never influences the content of our forecasts. Sponsor banners are clearly labelled, and details of how advertising cookies are used can be found in our Privacy Policy.
South Island Met Agency is an independent private forecaster and does not issue official government severe weather warnings. For official New Zealand watches and warnings, visit MetService. Read our About Us & Terms and Privacy Policy.