# Contra Calor — Vineyard GDD & Winkler Tracker

> Vineyard GDD & Winkler Tracker (iPhone/iPad app by SYBRAND ALBERTUS,STRAUSS VANZYL.)

- Source: https://appshunter.io/ios/app/contra-calor/id6761164191 (this page in markdown: same URL + `.md`)
- Developer: [SYBRAND ALBERTUS,STRAUSS VANZYL](https://appshunter.io/developer/1888086048)
- Category: Weather
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 15.0 · 13 MB
- Languages: American English
- Released: 2026-05-21
- Data updated: 2026-07-09
- User reviews in markdown: https://appshunter.io/ios/app/contra-calor/id6761164191/reviews.md

## What is Contra Calor?

Contra Calor is the viticulture Growing Degree Day tracker built for wine professionals. Pin your vineyard, pick your vintage, and get station-accurate heat accumulation data in seconds.

WHAT IS GDD?
Growing Degree Days (GDD) measure the heat accumulation a vineyard experiences during the growing season. GDD is a primary metric viticulture professionals use to predict grape maturity, plan harvest timing, and benchmark vintages year over year.

HOW IT WORKS
Drop a pin on your vineyard — anywhere in the world. Contra Calor pulls station-priority weather data from a global network of NOAA, ASOS, and personal weather stations, calculates your GDD accumulation from April 1 through October 31 (or set your own custom date range), and classifies your site on the Winkler scale.

VALIDATED ACCURACY
Independently validated against CIMIS (California Irrigation Management Information System) stations and Weather Underground personal weather stations across Napa Valley, Sonoma, and the Sierra Foothills. Average variance: 1.5–3.8% against ground truth data.

FEATURES
- GDD calculation for any vineyard location worldwide
- Winkler region classification (Regions I–V)
- Save vineyard profiles with nested vintage history
- Compare up to 3 vintages side by side
- Accumulation curve chart for each vintage
- Northern and Southern Hemisphere support
- °F and °C toggle
- Works offline after initial calculation

CONTRA CALOR PRO
Upgrade to Pro for unlimited vineyard profiles, full vintage history, 3-vintage comparison, and Southern Hemisphere support.

ABOUT THE NAME
Contra Calor — Spanish and Latin for both "Against the Heat" and "Counting Heat." 

Terms of Use: https://contracalor.com/terms.html
Privacy Policy: https://contracalor.com/privacy.html

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Contra Calor Pro | $4.99 | per month |
| Contra Calor Pro | $39.99 | per year |



## Version history (last 2 releases)

### 1.1 — 2026-05-24

Bug fixes and improvements:

- Fixed an issue where Pro subscription status was not always recognised immediately after purchase
- Improved Restore Purchases reliability
- Added "Request Pro Access" button for users seeking complimentary access

### 1.0 — 2026-05-21

No release notes.

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-09.*