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 2017-12-02.

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%
15991
33%
47738
19%
15947
63%
15947
46%
24138

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%
540
35%
1800
15%
540
58%
540
47%
798
May1st to 15thNight
39%
540
29%
1698
18%
540
58%
540
45%
827
May16th to endNight
47%
562
28%
1684
17%
561
63%
561
42%
891
June1st to 15thNight
52%
540
23%
1525
14%
540
61%
540
47%
802
June16th to endNight
64%
540
28%
1440
20%
540
69%
540
55%
753
July1st to 15thNight
76%
510
24%
1360
20%
510
78%
510
48%
750
July16th to endNight
82%
564
27%
1626
28%
531
83%
531
46%
851
August1st to 15thNight
79%
539
24%
1789
28%
536
79%
536
37%
946
August16th to endNight
75%
573
23%
1910
27%
573
77%
573
34%
1063
September1st to 15thNight
69%
540
24%
1824
25%
540
72%
540
33%
1032
September16th to endNight
63%
537
35%
1980
32%
537
71%
537
39%
954
October1st to 15thNight
52%
561
35%
2001
25%
561
66%
561
44%
928
October16th to endNight
61%
795
40%
2331
22%
795
72%
795
58%
1057
November1st to 15thNight
55%
950
37%
2470
16%
950
66%
950
61%
1195
November16th to endNight
51%
975
41%
2535
18%
975
63%
975
55%
1293
December1st to 15thNight
41%
910
36%
2366
14%
910
55%
910
45%
1304
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%313323346%61%
48696
Night
5%313323347%63%
47931
Cloud CoverDay
5%313323346%61%
48694
Night
5%313323347%63%
47931
TransparencyDay
22%49%21%26%16%
48392
Night
21%49%20%27%17%
47739
SeeingDay
6%7%24%33%22%5%
5826
Night
6%7%32%37%15%
15994

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
321111225%5%71%
2160
May1st to 15thDay
8%213323436%60%
2253
16th to endDay
6%212223346%63%
2430
June1st to 15thDay
311332445%7%61%
2430
16th to endDay
211232345%7%63%
2520
July1st to 15thDay
6%314425%5%5%8%51%
2520
16th to endDay
3213335%6%6%9%53%
2422
August1st to 15thDay
4212426%5%7%10%51%
2160
16th to endDay
6%425%5%3447%9%47%
2292
September1st to 15thDay
9%5%245%2446%8%45%
2135
16th to endDay
10%312312245%63%
1980
October1st to 15thDay
8%213212335%65%
1956
16th to endDay
31121223475%
1881
November1st to 15thDay
2212222336%71%
1718
16th to endDay
5%2132123470%
1755
December1st to 15thDay
5%413213347%62%
1631
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%
1800
May1st to 15thNight
5%212213336%66%
1697
16th to endNight
7%212322447%59%
1683
June1st to 15thNight
22332447%12%56%
1525
16th to endNight
2232347%9%62%
1440
July1st to 15thNight
5%2122246%6%11%55%
1440
16th to endNight
221333446%11%57%
1740
August1st to 15thNight
42235%35%5%8%10%49%
1800
16th to endNight
5%2145%35%5%6%11%50%
1910
September1st to 15thNight
8%41442346%7%51%
1824
16th to endNight
8%312222345%62%
1980
October1st to 15thNight
6%213312345%65%
2001
16th to endNight
32121233475%
2331
November1st to 15thNight
222212345%73%
2470
16th to endNight
321321323470%
2535
December1st to 15thNight
5%313323345%61%
2366
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%
2160
May1st to 15thDay
8%213323436%60%
2253
16th to endDay
6%213223445%62%
2430
June1st to 15thDay
321332345%7%61%
2430
16th to endDay
221232345%7%63%
2520
July1st to 15thDay
6%314435%5%6%8%51%
2520
16th to endDay
3213435%5%6%9%53%
2422
August1st to 15thDay
4213435%5%6%11%51%
2160
16th to endDay
6%425%43436%8%48%
2292
September1st to 15thDay
9%5%2443446%8%46%
2135
16th to endDay
9%312312235%63%
1980
October1st to 15thDay
8%213212345%65%
1956
16th to endDay
31121222475%
1881
November1st to 15thDay
2112222335%72%
1718
16th to endDay
5%2132223470%
1755
December1st to 15thDay
5%41321335%7%61%
1631
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%
1800
May1st to 15thNight
5%212213336%66%
1697
16th to endNight
7%312313447%59%
1683
June1st to 15thNight
22332446%12%56%
1525
16th to endNight
21232347%9%62%
1440
July1st to 15thNight
5%2122246%6%11%55%
1440
16th to endNight
221332446%11%57%
1740
August1st to 15thNight
42235%346%8%10%49%
1800
16th to endNight
5%2145%35%5%6%11%50%
1910
September1st to 15thNight
8%41442346%8%51%
1824
16th to endNight
8%312223345%62%
1980
October1st to 15thNight
6%313212336%64%
2001
16th to endNight
31121223474%
2331
November1st to 15thNight
222212245%73%
2470
16th to endNight
321221223470%
2535
December1st to 15thNight
6%313323346%61%
2366
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%20%30%24%
2160
May1st to 15thDay
24%48%17%22%23%
2253
16th to endDay
22%5%8%19%21%23%
2434
June1st to 15thDay
20%5%10%21%19%21%
2430
16th to endDay
18%6%11%22%20%20%
2520
July1st to 15thDay
28%7%12%20%20%10%
2371
16th to endDay
22%9%15%29%20%1
2274
August1st to 15thDay
23%9%17%27%17%3
2147
16th to endDay
31%7%13%21%20%5%
2292
September1st to 15thDay
34%7%12%20%18%6%
2135
16th to endDay
24%37%19%29%15%
1980
October1st to 15thDay
21%48%17%30%17%
1956
16th to endDay
14%35%19%38%19%
1881
November1st to 15thDay
15%27%20%36%18%
1718
16th to endDay
18%1317%34%23%
1755
December1st to 15thDay
23%29%26%30%8%
1631
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%37%19%26%25%
1800
May1st to 15thNight
19%410%15%25%23%
1698
16th to endNight
23%5%10%15%19%25%
1685
June1st to 15thNight
20%6%15%17%21%18%
1525
16th to endNight
16%6%16%24%17%18%
1440
July1st to 15thNight
20%7%16%26%20%9%
1360
16th to endNight
20%7%18%27%21%4
1626
August1st to 15thNight
25%7%19%24%16%6%
1789
16th to endNight
27%9%14%25%18%5%
1910
September1st to 15thNight
29%7%15%22%15%8%
1824
16th to endNight
23%47%21%27%15%
1980
October1st to 15thNight
21%38%19%28%18%
2001
16th to endNight
14%25%17%35%24%
2331
November1st to 15thNight
13%26%19%35%22%
2470
16th to endNight
18%2418%34%22%
2535
December1st to 15thNight
23%36%22%29%14%
2366
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%21%44%21%5%1
270
May1st to 15thDay
5%15%36%31%9%
390
16th to endDay
8%6%32%36%14%1
517
June1st to 15thDay
4327%39%22%3
495
16th to endDay
2116%39%32%6%
495
July1st to 15thDay
7%7%35%39%9%
475
16th to endDay
46%33%39%16%
411
August1st to 15thDay
316%40%38%8%
315
16th to endDay
9%113%37%29%9%
332
September1st to 15thDay
6%12%44%29%6%
290
16th to endDay
17%18%31%25%6%
135
October1st to 15thDay
12%25%34%20%5%
135
16th to endDay
4122%43%20%7%
144
November1st to 15thDay
5%5%33%29%15%10%
135
16th to endDay
10%16%34%23%10%4
135
December1st to 15thDay
5%7%50%27%8%1
94
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
540
May1st to 15thNight
6%10%42%35%6%
540
16th to endNight
8%5%35%38%11%
563
June1st to 15thNight
2338%45%9%
540
16th to endNight
2127%50%17%
540
July1st to 15thNight
6%12%49%30%1
510
16th to endNight
28%45%40%1
564
August1st to 15thNight
47%42%43%2
539
16th to endNight
5%11%44%36%1
573
September1st to 15thNight
9%13%46%29%
540
16th to endNight
9%318%45%21%1
537
October1st to 15thNight
9%430%39%15%1
561
16th to endNight
5%6%24%40%21%1
795
November1st to 15thNight
36%31%38%18%1
950
16th to endNight
5%8%31%36%17%1
975
December1st to 15thNight
8%9%38%34%9%
910
16th to endNight
8%14%39%29%8%
960
Page generated at 2017-12-03 09:16:39. Version ac04

Copyright 2017 A. Danko


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