Guadalupe River State Park
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Guadalupe River State Park clear sky chart from 2005-11-05 to 2019-06-10.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
48%
17698
25%
53922
17%
17652
56%
17652
32%
31739

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
38%
1048
27%
2717
12%
1045
47%
1045
31%
1726
January16th to endNight
36%
1004
29%
2796
12%
1004
48%
1004
30%
1736
February1st to 15thNight
31%
824
26%
2466
12%
818
43%
818
26%
1510
February16th to endNight
22%
736
25%
2206
7%
736
37%
736
25%
1343
March1st to 15thNight
28%
666
27%
2346
12%
666
44%
666
24%
1403
March16th to endNight
31%
672
22%
2464
14%
672
42%
672
24%
1448
April1st to 15thNight
28%
629
24%
2307
14%
629
45%
629
26%
1301
April16th to endNight
28%
624
25%
2036
14%
624
45%
624
26%
1262
May1st to 15thNight
33%
629
23%
1890
16%
629
42%
629
28%
1180
May16th to endNight
43%
658
24%
1972
16%
657
56%
657
33%
1172
June1st to 15thNight
62%
612
25%
1836
23%
612
70%
612
49%
929
June16th to endNight
63%
585
21%
1755
20%
585
68%
585
37%
1007
July1st to 15thNight
77%
555
19%
1665
20%
555
80%
555
41%
929
July16th to endNight
80%
612
24%
1738
26%
579
84%
579
44%
921
August1st to 15thNight
86%
575
28%
1816
34%
572
86%
572
50%
873
August16th to endNight
77%
621
19%
2125
23%
621
78%
621
34%
1194
September1st to 15thNight
72%
585
19%
2145
22%
585
72%
585
28%
1244
September16th to endNight
64%
582
23%
2145
24%
582
66%
582
26%
1287
October1st to 15thNight
68%
585
31%
2145
31%
585
72%
585
36%
1119
October16th to endNight
58%
821
35%
2485
23%
821
66%
821
44%
1297
November1st to 15thNight
50%
855
27%
2495
16%
855
55%
855
32%
1510
November16th to endNight
46%
1050
31%
2730
14%
1050
54%
1050
37%
1634
December1st to 15thNight
39%
1050
29%
2730
15%
1050
47%
1050
31%
1759
December16th to endNight
36%
1120
23%
2912
11%
1120
42%
1120
27%
1955

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
13%5%25%424446%44%
54579
Night
12%5%23323347%51%
54124
Cloud CoverDay
13%5%24424446%44%
54577
Night
13%5%23323347%51%
54124
TransparencyDay
39%49%19%17%8%
54277
Night
34%411%20%18%11%
53929
SeeingDay
15%5%21%30%21%5%
7558
Night
16%6%24%35%15%1
17702

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
17%424323225%48%
1881
16th to endDay
16%5%23222336%51%
2144
February1st to 15thDay
17%6%25%323336%45%
2050
16th to endDay
19%6%23322445%45%
1840
March1st to 15thDay
19%6%24423335%43%
2271
16th to endDay
17%5%24323345%45%
2464
April1st to 15thDay
15%5%25%413346%46%
2301
16th to endDay
15%6%25%434335%44%
2525
May1st to 15thDay
17%7%36%5%35%45%6%36%
2721
16th to endDay
16%6%25%435%5%5%7%36%
2846
June1st to 15thDay
5%425%5%46%6%6%8%45%
2653
16th to endDay
11%5%36%7%35%5%6%8%35%
2535
July1st to 15thDay
10%5%25%5%35%5%6%9%40%
2535
16th to endDay
7%324436%5%5%11%44%
2674
August1st to 15thDay
321343445%10%57%
2383
16th to endDay
8%435%6%45%5%6%8%41%
2429
September1st to 15thDay
12%6%36%7%35%45%6%37%
2145
16th to endDay
11%5%35%6%345%6%7%40%
2145
October1st to 15thDay
11%5%24434346%49%
2142
16th to endDay
12%313213345%59%
2080
November1st to 15thDay
14%6%36%5%3435%5%42%
2019
16th to endDay
13%5%2342333453%
1890
December1st to 15thDay
20%6%24422335%44%
1890
16th to endDay
17%8%2442333445%
2016
January1st to 15thNight
17%5%13323336%49%
2717
16th to endNight
15%6%23323335%50%
2796
February1st to 15thNight
17%7%13313235%50%
2462
16th to endNight
18%5%13323335%47%
2206
March1st to 15thNight
17%6%24413336%47%
2346
16th to endNight
15%6%24323346%46%
2464
April1st to 15thNight
13%5%24323347%48%
2307
16th to endNight
17%5%24423335%47%
2036
May1st to 15thNight
14%5%34324446%45%
1889
16th to endNight
10%5%1442345%10%47%
1971
June1st to 15thNight
4212323349%62%
1836
16th to endNight
7%32432346%8%53%
1755
July1st to 15thNight
6%2132245%6%11%52%
1755
16th to endNight
5%21232346%10%56%
1846
August1st to 15thNight
22231435%11%63%
1826
16th to endNight
7%4134345%6%10%49%
2125
September1st to 15thNight
10%5%243245%5%8%47%
2145
16th to endNight
10%5%25%43345%8%44%
2145
October1st to 15thNight
9%313323346%56%
2145
16th to endNight
11%312212225%63%
2485
November1st to 15thNight
12%5%24423336%51%
2495
16th to endNight
14%5%13212225%56%
2730
December1st to 15thNight
18%5%24313236%48%
2730
16th to endNight
18%7%2432233445%
2912

Percentage Cloud Cover SE (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
17%424323335%49%
1881
16th to endDay
15%5%13322336%51%
2144
February1st to 15thDay
17%6%25%423345%45%
2050
16th to endDay
19%6%24312445%45%
1840
March1st to 15thDay
19%6%23423336%43%
2271
16th to endDay
17%6%24323345%45%
2462
April1st to 15thDay
15%5%24423346%45%
2301
16th to endDay
15%6%25%434335%44%
2525
May1st to 15thDay
17%6%36%5%3445%6%36%
2721
16th to endDay
16%6%35%5%35%5%5%7%36%
2846
June1st to 15thDay
5%425%5%46%6%6%8%45%
2653
16th to endDay
11%6%36%6%45%5%6%7%35%
2535
July1st to 15thDay
10%425%5%35%6%5%9%39%
2535
16th to endDay
8%3245%36%5%6%10%45%
2674
August1st to 15thDay
321333445%10%57%
2383
16th to endDay
8%5%35%6%45%5%6%8%40%
2429
September1st to 15thDay
13%7%36%6%35%45%6%37%
2145
16th to endDay
12%5%35%5%35%5%6%7%40%
2145
October1st to 15thDay
11%424424447%49%
2142
16th to endDay
12%313312345%59%
2080
November1st to 15thDay
14%7%35%5%2435%5%41%
2019
16th to endDay
13%5%2441234453%
1890
December1st to 15thDay
20%5%24323335%44%
1890
16th to endDay
17%7%2441343445%
2016
January1st to 15thNight
17%5%13323335%50%
2717
16th to endNight
15%5%23323335%50%
2796
February1st to 15thNight
17%7%2331223450%
2462
16th to endNight
18%5%14323336%47%
2206
March1st to 15thNight
17%7%13423336%47%
2346
16th to endNight
16%6%2422335%5%46%
2464
April1st to 15thNight
13%5%24322346%49%
2307
16th to endNight
17%5%25%423335%48%
2036
May1st to 15thNight
14%6%24333446%45%
1889
16th to endNight
10%5%1442346%9%47%
1971
June1st to 15thNight
5%11332235%8%62%
1836
16th to endNight
8%32332346%8%52%
1755
July1st to 15thNight
6%213325%5%6%11%51%
1755
16th to endNight
6%21232336%9%57%
1846
August1st to 15thNight
22232335%10%63%
1826
16th to endNight
7%3134245%6%10%49%
2125
September1st to 15thNight
10%5%243245%5%8%46%
2145
16th to endNight
10%5%25%433449%44%
2145
October1st to 15thNight
10%314323346%57%
2145
16th to endNight
11%313212235%63%
2485
November1st to 15thNight
12%5%24422336%51%
2495
16th to endNight
14%5%13213225%56%
2730
December1st to 15thNight
18%5%24312246%48%
2730
16th to endNight
17%8%2432333445%
2912

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
39%3418%19%14%
1882
16th to endDay
36%36%15%25%14%
2144
February1st to 15thDay
42%25%14%18%16%
2051
16th to endDay
41%35%16%19%12%
1840
March1st to 15thDay
44%47%14%17%12%
2271
16th to endDay
40%38%17%18%10%
2464
April1st to 15thDay
40%37%17%18%12%
2301
16th to endDay
44%35%19%17%10%
2525
May1st to 15thDay
48%5%8%14%17%5%
2721
16th to endDay
46%6%9%19%15%3
2850
June1st to 15thDay
34%6%10%23%20%4
2653
16th to endDay
44%7%10%21%13%2
2535
July1st to 15thDay
37%7%16%24%12%1
2396
16th to endDay
32%7%18%29%12%
2519
August1st to 15thDay
22%5%17%37%16%1
2369
16th to endDay
39%7%15%23%11%2
2429
September1st to 15thDay
46%6%10%17%15%4
2145
16th to endDay
41%7%10%18%15%7%
2145
October1st to 15thDay
35%5%11%18%18%10%
2142
16th to endDay
28%3416%25%20%
2080
November1st to 15thDay
43%47%19%15%9%
2019
16th to endDay
35%25%15%22%18%
1890
December1st to 15thDay
44%25%17%18%10%
1890
16th to endDay
43%36%14%21%10%
2016
January1st to 15thNight
37%36%16%19%17%
2717
16th to endNight
37%3415%22%16%
2796
February1st to 15thNight
38%35%14%19%18%
2472
16th to endNight
40%25%16%20%15%
2206
March1st to 15thNight
40%38%15%17%14%
2346
16th to endNight
38%410%16%19%10%
2464
April1st to 15thNight
36%38%18%18%15%
2307
16th to endNight
40%47%19%16%11%
2036
May1st to 15thNight
38%411%19%16%8%
1890
16th to endNight
33%5%13%28%14%3
1973
June1st to 15thNight
20%5%14%30%24%4
1836
16th to endNight
29%6%17%28%14%2
1755
July1st to 15thNight
22%9%23%29%13%1
1665
16th to endNight
20%8%24%33%11%1
1738
August1st to 15thNight
16%6%21%38%15%1
1816
16th to endNight
29%7%24%26%9%2
2125
September1st to 15thNight
35%6%16%21%15%4
2145
16th to endNight
36%7%13%19%15%7%
2145
October1st to 15thNight
28%413%24%17%11%
2145
16th to endNight
26%25%17%27%21%
2485
November1st to 15thNight
35%49%21%17%11%
2495
16th to endNight
31%36%17%21%19%
2730
December1st to 15thNight
39%26%18%21%10%
2730
16th to endNight
43%25%13%21%12%
2912

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
21%12%34%22%7%
180
16th to endDay
20%11%33%24%9%
192
February1st to 15thDay
25%17%30%20%6%
180
16th to endDay
28%18%35%16%1
159
March1st to 15thDay
24%13%41%15%5%
180
16th to endDay
16%6%42%27%6%
192
April1st to 15thDay
16%12%42%22%5%
180
16th to endDay
16%12%38%26%5%
417
May1st to 15thDay
22%8%33%26%7%
618
16th to endDay
20%5%28%32%11%1
677
June1st to 15thDay
8%115%47%25%3
616
16th to endDay
12%310%39%27%6%
570
July1st to 15thDay
9%19%36%34%8%
550
16th to endDay
6%1429%48%9%
595
August1st to 15thDay
5%1434%42%12%
447
16th to endDay
12%15%33%34%12%
341
September1st to 15thDay
17%25%18%41%16%
180
16th to endDay
12%27%23%41%13%
180
October1st to 15thDay
7%9%34%35%13%
180
16th to endDay
26%5%18%24%22%3
192
November1st to 15thDay
31%5%22%26%11%2
180
16th to endDay
18%15%28%22%11%4
180
December1st to 15thDay
25%8%29%20%12%4
180
16th to endDay
30%8%36%19%4
192
January1st to 15thNight
20%10%26%31%9%
1050
16th to endNight
20%9%29%31%8%
1004
February1st to 15thNight
23%12%29%28%6%
824
16th to endNight
24%11%39%22%1
736
March1st to 15thNight
20%9%37%27%4
666
16th to endNight
18%9%37%29%4
672
April1st to 15thNight
15%11%41%27%3
629
16th to endNight
20%5%43%25%5%
624
May1st to 15thNight
15%8%40%30%4
630
16th to endNight
13%434%35%11%
659
June1st to 15thNight
5%27%47%17%1
612
16th to endNight
7%119%49%20%1
585
July1st to 15thNight
6%10%48%30%3
555
16th to endNight
7%451%32%3
612
August1st to 15thNight
25%49%37%4
575
16th to endNight
9%446%34%4
621
September1st to 15thNight
13%5%37%36%6%
585
16th to endNight
13%19%32%37%5%
582
October1st to 15thNight
11%112%41%27%4
585
16th to endNight
12%421%34%24%2
821
November1st to 15thNight
14%6%23%35%17%1
855
16th to endNight
17%9%22%32%15%1
1050
December1st to 15thNight
22%10%24%31%10%1
1050
16th to endNight
23%9%25%33%8%
1120
Page generated at 2019-06-10 18:29:45. Version ac04

Copyright 2019 A. Danko


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