Clovis
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Clovis clear sky chart from 2005-11-05 to 2017-04-30.

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
50%
15262
33%
45542
19%
15218
63%
15218
46%
23025

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
41%
872
31%
2479
14%
868
57%
868
49%
1245
January16th to endNight
41%
768
40%
2369
20%
768
62%
768
49%
1114
February1st to 15thNight
37%
703
32%
2112
16%
700
53%
700
40%
1077
February16th to endNight
33%
632
38%
1894
12%
632
57%
632
46%
920
March1st to 15thNight
42%
720
33%
2160
16%
720
56%
720
43%
1095
March16th to endNight
34%
621
34%
2004
16%
621
54%
621
44%
963
April1st to 15thNight
29%
539
33%
1798
14%
539
53%
539
40%
870
April16th to endNight
30%
537
35%
1790
15%
537
58%
537
47%
792
May1st to 15thNight
39%
495
31%
1557
18%
495
59%
495
44%
770
May16th to endNight
48%
514
26%
1540
17%
513
62%
513
41%
831
June1st to 15thNight
49%
495
24%
1398
14%
495
59%
495
46%
742
June16th to endNight
64%
495
26%
1320
20%
495
69%
495
56%
687
July1st to 15thNight
76%
465
26%
1240
22%
465
79%
465
47%
689
July16th to endNight
82%
522
25%
1496
27%
489
83%
489
46%
787
August1st to 15thNight
81%
494
25%
1639
31%
491
81%
491
39%
840
August16th to endNight
75%
525
22%
1750
25%
525
77%
525
34%
977
September1st to 15thNight
66%
495
25%
1672
25%
495
70%
495
31%
975
September16th to endNight
65%
492
35%
1815
32%
492
74%
492
42%
845
October1st to 15thNight
53%
514
37%
1834
26%
514
67%
514
45%
842
October16th to endNight
61%
729
38%
2137
22%
729
71%
729
58%
968
November1st to 15thNight
56%
875
38%
2275
16%
875
68%
875
62%
1090
November16th to endNight
50%
900
39%
2340
17%
900
62%
900
53%
1210
December1st to 15thNight
41%
900
36%
2340
14%
900
55%
900
46%
1286
December16th to endNight
35%
960
34%
2583
14%
960
50%
960
42%
1410

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
5%31332335%6%61%
46171
Night
5%313323347%63%
45735
Cloud CoverDay
5%313323346%61%
46169
Night
5%313323347%63%
45735
TransparencyDay
22%49%20%26%16%
45867
Night
21%49%20%27%17%
45543
SeeingDay
6%7%25%34%21%4
4974
Night
6%7%32%37%15%
15265

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
4313212346%65%
1471
16th to endDay
4212312346%66%
1851
February1st to 15thDay
4413311235%67%
1750
16th to endDay
35%24212345%65%
1580
March1st to 15thDay
5%31232335%7%61%
1800
16th to endDay
3313313247%65%
2216
April1st to 15thDay
5%313313345%64%
2150
16th to endDay
321211225%5%71%
2149
May1st to 15thDay
8%213323436%59%
2064
16th to endDay
6%212323445%62%
2222
June1st to 15thDay
311342445%7%60%
2227
16th to endDay
211242445%8%62%
2310
July1st to 15thDay
7%414425%5%6%8%49%
2310
16th to endDay
3213335%6%6%9%53%
2244
August1st to 15thDay
32125%25%5%7%10%52%
1980
16th to endDay
6%425%5%3447%9%47%
2100
September1st to 15thDay
10%5%345%25%46%8%43%
1957
16th to endDay
7%312312245%65%
1815
October1st to 15thDay
8%213212345%65%
1793
16th to endDay
31221223475%
1724
November1st to 15thDay
2112212235%73%
1583
16th to endDay
6%2133223469%
1620
December1st to 15thDay
5%412213347%62%
1620
16th to endDay
6%5%1332335%7%57%
1635
January1st to 15thNight
4213213335%66%
2479
16th to endNight
4212223236%67%
2369
February1st to 15thNight
5%313322435%64%
2102
16th to endNight
6%311213347%63%
1894
March1st to 15thNight
5%313213447%61%
2160
16th to endNight
5%322322335%65%
2004
April1st to 15thNight
6%312213346%63%
1798
16th to endNight
4212213236%69%
1790
May1st to 15thNight
5%212213336%66%
1556
16th to endNight
8%312322447%58%
1539
June1st to 15thNight
221332447%12%56%
1398
16th to endNight
1231347%9%62%
1320
July1st to 15thNight
5%2122246%6%11%54%
1320
16th to endNight
221333446%11%56%
1610
August1st to 15thNight
31235%25%5%8%10%51%
1650
16th to endNight
5%2145%35%5%6%11%49%
1750
September1st to 15thNight
9%41442346%7%50%
1672
16th to endNight
6%312222346%64%
1815
October1st to 15thNight
6%213212345%65%
1834
16th to endNight
32121233474%
2137
November1st to 15thNight
112112345%74%
2275
16th to endNight
431321323469%
2340
December1st to 15thNight
6%313323345%61%
2340
16th to endNight
6%5%13322337%60%
2583

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
4323212345%66%
1471
16th to endDay
4312323336%66%
1851
February1st to 15thDay
4413312235%67%
1750
16th to endDay
3424212345%65%
1580
March1st to 15thDay
5%31232245%7%61%
1800
16th to endDay
3313213247%65%
2214
April1st to 15thDay
5%213313345%64%
2150
16th to endDay
321111225%6%71%
2149
May1st to 15thDay
8%213323436%59%
2064
16th to endDay
6%213223445%62%
2222
June1st to 15thDay
311342345%7%60%
2227
16th to endDay
221242445%8%62%
2310
July1st to 15thDay
7%414435%5%6%8%49%
2310
16th to endDay
3213335%5%6%9%53%
2244
August1st to 15thDay
3213425%5%6%10%52%
1980
16th to endDay
6%425%43446%8%48%
2100
September1st to 15thDay
10%5%345%345%6%8%43%
1957
16th to endDay
7%312312235%65%
1815
October1st to 15thDay
8%213212345%65%
1793
16th to endDay
31121223475%
1724
November1st to 15thDay
2112222235%73%
1583
16th to endDay
6%2133223469%
1620
December1st to 15thDay
5%41221335%7%62%
1620
16th to endDay
6%5%2322335%7%58%
1635
January1st to 15thNight
4213213336%66%
2479
16th to endNight
4213223236%67%
2369
February1st to 15thNight
5%313322435%64%
2102
16th to endNight
6%31122335%7%63%
1894
March1st to 15thNight
5%313212447%61%
2160
16th to endNight
5%312212335%65%
2004
April1st to 15thNight
6%312213336%64%
1798
16th to endNight
4312212236%69%
1790
May1st to 15thNight
5%312213336%66%
1556
16th to endNight
7%312323447%58%
1539
June1st to 15thNight
22133245%6%12%55%
1398
16th to endNight
11231447%10%62%
1320
July1st to 15thNight
5%2123246%6%11%54%
1320
16th to endNight
22133245%6%11%56%
1610
August1st to 15thNight
31235%35%5%8%10%51%
1650
16th to endNight
5%2145%35%5%6%11%49%
1750
September1st to 15thNight
9%41442345%7%50%
1672
16th to endNight
6%32223345%64%
1815
October1st to 15thNight
6%313212336%64%
1834
16th to endNight
32111223474%
2137
November1st to 15thNight
122212245%74%
2275
16th to endNight
421321323469%
2340
December1st to 15thNight
6%313323345%61%
2340
16th to endNight
6%5%13322337%60%
2583

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
20%37%27%26%14%
1472
16th to endDay
20%26%20%33%16%
1851
February1st to 15thDay
21%27%20%28%18%
1751
16th to endDay
22%2414%37%18%
1580
March1st to 15thDay
22%26%18%32%17%
1800
16th to endDay
20%25%21%28%20%
2216
April1st to 15thDay
21%36%14%30%23%
2150
16th to endDay
14%27%19%30%24%
2149
May1st to 15thDay
25%48%17%19%24%
2064
16th to endDay
23%5%8%18%20%23%
2226
June1st to 15thDay
21%5%10%21%19%20%
2227
16th to endDay
18%6%12%22%19%19%
2310
July1st to 15thDay
30%7%12%21%19%8%
2161
16th to endDay
22%8%16%29%20%1
2096
August1st to 15thDay
23%8%17%28%18%4
1967
16th to endDay
31%7%14%22%20%4
2100
September1st to 15thDay
37%8%13%18%15%6%
1957
16th to endDay
22%37%19%30%15%
1815
October1st to 15thDay
21%49%17%30%17%
1793
16th to endDay
14%35%19%38%20%
1724
November1st to 15thDay
14%16%20%37%19%
1583
16th to endDay
19%1316%33%24%
1620
December1st to 15thDay
22%28%26%30%8%
1620
16th to endDay
25%29%23%27%10%
1635
January1st to 15thNight
20%28%22%31%14%
2479
16th to endNight
19%26%19%32%20%
2369
February1st to 15thNight
24%35%17%27%21%
2112
16th to endNight
20%25%16%31%23%
1894
March1st to 15thNight
22%35%19%29%19%
2160
16th to endNight
21%37%19%24%23%
2004
April1st to 15thNight
22%38%16%27%22%
1798
16th to endNight
17%27%19%26%25%
1790
May1st to 15thNight
20%5%10%15%23%25%
1557
16th to endNight
25%5%10%14%19%24%
1541
June1st to 15thNight
20%6%15%17%21%17%
1398
16th to endNight
15%6%17%23%18%17%
1320
July1st to 15thNight
21%7%16%26%19%8%
1240
16th to endNight
20%7%18%26%21%4
1496
August1st to 15thNight
23%7%19%25%17%6%
1639
16th to endNight
26%9%15%24%18%5%
1750
September1st to 15thNight
31%8%15%20%14%8%
1672
16th to endNight
21%47%22%28%14%
1815
October1st to 15thNight
21%38%20%28%17%
1834
16th to endNight
14%25%17%36%23%
2137
November1st to 15thNight
12%26%18%36%23%
2275
16th to endNight
19%2416%33%23%
2340
December1st to 15thNight
23%36%22%29%15%
2340
16th to endNight
25%27%20%33%10%
2583

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
12%7%42%20%13%4
90
16th to endDay
17%35%34%10%2
96
February1st to 15thDay
7%8%28%34%18%1
90
16th to endDay
7%9%38%29%13%1
81
March1st to 15thDay
1443%30%21%
90
16th to endDay
422%34%26%11%
246
April1st to 15thDay
7%21%42%20%8%
269
16th to endDay
5%20%44%21%5%1
267
May1st to 15thDay
6%16%37%30%8%
321
16th to endDay
9%6%29%38%14%1
437
June1st to 15thDay
4428%41%19%1
420
16th to endDay
2116%40%32%6%
420
July1st to 15thDay
8%8%36%39%6%
400
16th to endDay
46%34%39%14%
350
August1st to 15thDay
216%42%36%10%
255
16th to endDay
9%114%41%27%5%
268
September1st to 15thDay
8%15%46%26%3
232
16th to endDay
7%117%35%28%8%
90
October1st to 15thDay
14%26%33%20%5%
90
16th to endDay
7%117%44%22%6%
96
November1st to 15thDay
6%5%27%26%18%14%
90
16th to endDay
15%15%32%24%8%3
90
December1st to 15thDay
5%7%50%26%8%1
90
16th to endDay
10%19%43%22%3
96
January1st to 15thNight
5%8%40%33%10%1
873
16th to endNight
5%9%40%33%9%
768
February1st to 15thNight
7%14%38%31%7%
704
16th to endNight
8%11%44%30%3
632
March1st to 15thNight
7%13%35%36%8%
720
16th to endNight
6%10%45%30%6%
621
April1st to 15thNight
6%15%46%26%4
539
16th to endNight
412%50%27%4
537
May1st to 15thNight
6%10%42%35%6%
495
16th to endNight
9%433%39%12%
515
June1st to 15thNight
3439%44%7%
495
16th to endNight
2126%50%17%
495
July1st to 15thNight
6%11%50%29%1
465
16th to endNight
29%45%40%2
522
August1st to 15thNight
26%42%45%2
494
16th to endNight
411%44%36%1
525
September1st to 15thNight
9%14%47%26%
495
16th to endNight
8%218%45%23%1
492
October1st to 15thNight
8%430%39%15%1
514
16th to endNight
5%6%23%41%20%2
729
November1st to 15thNight
27%30%37%19%1
875
16th to endNight
5%8%31%36%16%1
900
December1st to 15thNight
8%9%38%34%9%
900
16th to endNight
8%14%39%29%8%
960
Page generated at 2017-04-30 18:40:03. Version ac04

Copyright 2017 A. Danko


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