My La Crosse weather station measures temperature in different locations, rainfall, wind etc. The measurements are made 24/7, with some occasional down times, every 5 minutes or so and then dumped into a database. Each set of data had about 6000 data points.Today, on the 31st of December, I queried the data and here is what I have learned after doing some math.
1. Temperatures outdoors
Here Delta t is the longevity in time of a certain temperature during the day, normally in 5 minute time intervals, at which the measurements were coming through. The averaging was done by time, to understand the cumulative effects of the temperature on the plant growth.
After all this effort, the 'global time-averaged temperature' came out to be 58.7 F.
Global time-averaged temperature in Julian greenhouse was 66.8 F. Global maximum was 127F, the global minimum was 29.8 F. Note that the vents were installed in February which caused some drop in T. The first two months of data therefore were queried without the vents, so the data may be somewhat an overestimate as the vents is the default mode of use. The vents were designed to open at about 20 C (68 F) internal temperature, and close back when the temperature drops. One can see that they did the job to a degree to keep the temperature constant, up to May. In June-December, the spikes to 100 F became common. September was the hottest month with spikes up to 120 F in the greenhouse.
The literature data from the Western Regional Weather Center quote average maximum and average minimum temperatures in Julian from 1981 to 2010, see below.
Julian 1981-2010 Monthly Climate Summary, Western Regional Weather Center
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual | |
| Average Max. Temperature (F) | 57.7 | 60.2 | 62.1 | 68.6 | 76.2 | 85.4 | 91.5 | 91.4 | 84.2 | 72.9 | 60.9 | 57.3 | 72.6 |
| Average Min. Temperature (F) | 36.8 | 37.0 | 36.9 | 39.7 | 43.3 | 48.4 | 54.6 | 56.4 | 52.1 | 45.8 | 38.5 | 36.4 | 43.9 |
| Average Total Precipitation (in.) | 3.41 | 4.19 | 4.79 | 2.04 | 0.57 | 0.16 | 0.51 | 1.47 | 1.03 | 1.73 | 3.87 | 4.00 | 27.75 |
The average maximum temperature is defined as the average of daily maximum temperatures measured over the month. Similarly, the average minimum temperature is an average of daily minimum temperatures. The annual data are the average of the monthly averages. The midpoint between the annual average max and min came to 58.25 F, which is similar to our time-averaged value of 58.7F; these values do not need to be the same (as the process of averaging is different) but the fact that they are close is a good sign.
In terms of the temperature extremes, the global maximum was 114.3F, the global minimum was 25 F. As expected, they are more extreme than the 'smoothened' monthly averaged values shown above in the Western Report, which were 91.5 F (July) and 36.4 F (December).
2. Chilling hours and Winkler Index
Chilling is required for the fruit trees to develop leaves and fruit. There are multiple ways to determine those hours and I chose the simplest one. I just integrated the total time during the year when the temperature outside was below 45 F. The outcome was 1710 hours, which was more than 1000 hours required for most varieties of apples and pears.
Winkler Index is the metrics used to characterize if the climate is suitable for growing grapes, and is used to determine which varieties of grapes will do well in a given climate. By definition, Winkler Index is measured as the sum of days of the year with the average temperature above 50 F, multiplied by the average temperature excess over 50 F, measured on that day. (The units of Winkler Index are therefore days*degrees F). The summation is done only from April the 1st through September the 30th; the other days are excluded as not relevant for growing grapes; similarly, if the average temperature falls below 50 F, those days are excluded as well (i.e., there is no negative contribution to the index). The outcome was 3487, which is comparable to Ramona (3470) and Escondido (3510). It corresponds to Region 3 of the Winkler Index, and lies on the higher end of it.
Footnote: My calculation did not do the daily averaging; that is, every time the temperature was above 50 F, the Winkler Index was incremented, even if it happened for a fraction of a day. That is, if there was a day with the low temperature at night , the daily average may be below 50 and this day would normally be excluded from the summation (?). Perhaps I need to correct for it, to be more inline with the normal process.
Footnote to Footnote: after this correction, Winkler Index came to 3287, Which is still Region 3, but mid-range (close to the one of Poway). It is not very clear to me, why Poway's index is lower than the one of Ramona and Escondido-- I would think it is the other way around.
3. Temperature in the greenhouse
Global time-averaged temperature in Julian greenhouse was 66.8 F. Global maximum was 127F, the global minimum was 29.8 F. Note that the vents were installed in February which caused some drop in T. The first two months of data therefore were queried without the vents, so the data may be somewhat an overestimate as the vents is the default mode of use. The vents were designed to open at about 20 C (68 F) internal temperature, and close back when the temperature drops. One can see that they did the job to a degree to keep the temperature constant, up to May. In June-December, the spikes to 100 F became common. September was the hottest month with spikes up to 120 F in the greenhouse.
To summirize, the average T in the greenhouse was higher by 8.1 F than outdoors. The maximum was higher by 12.7F. The minimum was higher by 4.8F.
Chilling hours in the greenhouse were reduced to 730 hours. It may be still sufficient for some plants.
4. Temperature in the yurt
Temperatures in the yurt were in between those of the Greenhouse and the outside probe. The table below compares averages, maxima and minima of the temperatures between these three locations.
Temperature Average Maximum Minimum Chilling hours
Outdoors 58.7 114.3 25 1700
Greenhouse 66.8 127 29.8 730
Yurt 63.0 107.8 28 n/a
5. Rainfall
Whereas the temperature data are quite robust, it is not quite clear how good is the rain sensor, and if the precipitation data as collected are correct. The sensor was never calibrated. Also, by design, the water that comes as the snow/hail mostly remains unmeasured by the probe, as it may just slide off the surface of the probe without melting and remain undetected.
The bottomline is, only 12.51 inches of rain was detected in Julian in 2024. It is slightly less than half of the historic average of 27.75 inches shown in the Western report. It indicates a very dry year, and is in agreement with the observations of our neighbors.
To further validate it, another tidbit of information is the rainfall measurements made by the same probe from April 2022 to February of 2023. The data is available only about 10 months total, excluding the potentially rainy days of February-March. The total rainfall came to 25 inches, in line with the
historic average. It may indicate that the probe is fully functional, and the 2X lower rainfall is real.
6. Wind
