Chill hours in Modesto, California: the last 10 winters
Ten seasons of winter chill for Modesto, California (37.6391, -120.9969), calculated from NASA POWER hourly temperatures across 2016–17 to 2025–26. Instead of comparing winters yourself or hunting for the nearest weather station, the three standard models for fruit trees and berries are already worked out below.
How the last season compared
The 2025–26 season delivered 815 chill hours, 86 below the ten-season average of 901. That is a difference of 10%. It was the fourth-lowest of the ten seasons recorded here. Chill portions, which discount warm spells differently, came to 70.9 against a ten-season average of 86.2.
Ten-season average, low, and high
| Model | Average | Lowest season | Highest season |
|---|---|---|---|
| 45°F Hours Hours between 0 and 7.2°C (32–45°F). | 900.8 hours | 620.0 | 1311.0 |
| Utah Weighted bands; warm hours subtract from the total. | 1403.3 units | 1187.0 | 1920.5 |
| Dynamic Fishman–Erez model; handles warm spells. | 86.2 portions | 70.9 | 105.4 |
45°F Hours and Utah are counted over 1 November – 28 February, following the UC Davis convention. Dynamic is counted over 1 September – 31 March.
Season by season
| Season | 45°F Hours | Utah units | Chill portions |
|---|---|---|---|
| 2016–17 | 1015 | 1469.0 | 86.0 |
| 2017–18 | 776 | 1187.0 | 80.5 |
| 2018–19 | 862 | 1421.5 | 89.9 |
| 2019–20 | 851 | 1322.0 | 81.2 |
| 2020–21 | 1045 | 1512.5 | 88.6 |
| 2021–22 | 930 | 1426.0 | 83.7 |
| 2022–23 | 1311 | 1920.5 | 105.4 |
| 2023–24 | 620 | 1214.5 | 86.8 |
| 2024–25 | 783 | 1347.0 | 88.6 |
| 2025–26 | 815 | 1213.5 | 70.9 |
Which fruit varieties suit Modesto?
The 3 most chill-demanding varieties that still fit an average of 901 chill hours here.
| Variety | Species | Chill requirement |
|---|---|---|
| Honeycrisp | Apple | 800 hours |
| Cortland | Apple | 800 hours |
| Cox Orange Pippin | Apple | 800 hours |
Station data for California
NASA POWER is a grid estimate. For measured station data and local chill guidance, see UC Davis Fruit & Nut Research and Information Center: chilling hours, units, and portions.
Nearby locations
- Watsonville, California — 105 km
- Fresno, California — 147 km
Track this season in ChillCast
ChillCast tracks this season's chill for Modesto, California on your iPhone and compares it with the ten-season average above.
Generated
This page was generated on 2026-09-06.
About this data
Values are NASA POWER regional estimates (about 0.5° grid), not orchard measurements. Check your local extension service for station data.
Source: NASA POWER hourly 2-metre air temperature (MERRA-2). NASA does not endorse ChillCast.