Quartzsite
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Quartzsite clear sky chart from 2005-11-06 to 2024-01-13.

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
76%
24449
39%
74364
33%
24404
82%
24404
60%
33000

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 10thNight
73%
760
36%
2457
35%
756
79%
756
49%
1149
January11th to 20thNight
72%
732
38%
2379
36%
732
79%
732
51%
1092
January21st to endNight
64%
792
41%
2507
36%
792
75%
792
48%
1213
February1st to 10thNight
70%
720
41%
2160
36%
720
80%
720
55%
1002
February11th to 20thNight
65%
700
38%
2098
33%
700
75%
700
51%
1018
February21st to endNight
61%
592
37%
1776
34%
592
72%
592
51%
849
March1st to 10thNight
63%
720
35%
2102
28%
720
74%
720
54%
995
March11th to 20thNight
68%
720
40%
1980
31%
720
78%
720
61%
942
March21st to endNight
64%
792
38%
2178
26%
792
74%
792
59%
1042
April1st to 10thNight
67%
720
37%
1954
22%
720
75%
720
62%
919
April11th to 20thNight
62%
711
42%
1779
21%
711
74%
711
70%
844
April21st to endNight
69%
577
48%
1657
29%
577
81%
577
76%
670
May1st to 10thNight
71%
540
44%
1620
30%
540
80%
540
73%
637
May11th to 20thNight
74%
531
43%
1594
30%
531
81%
531
74%
629
May21st to endNight
74%
582
42%
1746
28%
582
82%
582
80%
653
June1st to 10thNight
82%
540
38%
1620
31%
540
85%
540
75%
647
June11th to 20thNight
84%
540
41%
1620
32%
540
88%
540
84%
595
June21st to endNight
86%
540
37%
1620
31%
540
88%
540
77%
632
July1st to 10thNight
90%
525
34%
1575
29%
525
90%
525
66%
675
July11th to 20thNight
87%
522
33%
1566
28%
522
88%
522
56%
727
July21st to endNight
84%
591
34%
1674
28%
558
86%
558
52%
824
August1st to 10thNight
89%
537
39%
1602
30%
534
90%
534
64%
694
August11th to 20thNight
88%
681
38%
1749
26%
681
89%
681
64%
877
August21st to endNight
89%
792
42%
1980
31%
792
90%
792
69%
962
September1st to 10thNight
86%
720
37%
1962
31%
720
88%
720
65%
920
September11th to 20thNight
88%
720
47%
1980
42%
720
91%
720
79%
827
September21st to endNight
85%
720
44%
1980
36%
720
91%
720
75%
853
October1st to 10thNight
77%
720
42%
1980
35%
720
83%
720
66%
910
October11th to 20thNight
85%
720
49%
2060
43%
720
91%
720
79%
829
October21st to endNight
81%
792
47%
2376
41%
792
88%
792
74%
932
November1st to 10thNight
80%
740
42%
2373
40%
740
87%
740
64%
972
November11th to 20thNight
80%
760
42%
2470
43%
760
87%
760
64%
1014
November21st to endNight
70%
760
41%
2470
37%
760
79%
760
55%
1078
December1st to 10thNight
72%
760
39%
2470
38%
760
78%
760
49%
1154
December11th to 20thNight
70%
759
36%
2927
36%
758
77%
758
38%
1455
December21st to endNight
66%
821
25%
4323
34%
817
75%
817
34%
1769

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
2212223345%74%
74905
Night
2212223345%73%
74883
TransparencyDay
14%2311%25%44%
74632
Night
14%2311%24%45%
74678
SeeingDay
3416%33%32%12%
14156
Night
3314%39%35%6%
24471

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 10thDay
432342335%7%65%
1708
11th to 20thDay
431321235%6%69%
1642
21st to endDay
5%213323446%67%
1845
February1st to 10thDay
3213313336%71%
1800
11th to 20thDay
321342335%6%67%
1750
21st to endDay
3213333335%70%
1480
March1st to 10thDay
411232345%8%68%
1858
11th to 20thDay
3212213346%71%
1980
21st to endDay
221331233476%
2178
April1st to 10thDay
1211323347%72%
2002
11th to 20thDay
22121223481%
2129
21st to endDay
1111211235%82%
2300
May1st to 10thDay
1111112245%80%
2340
11th to 20thDay
11111123485%
2301
21st to endDay
11111112388%
2530
June1st to 10thDay
111121222484%
2340
11th to 20thDay
11111111391%
2340
21st to endDay
111111222385%
2340
July1st to 10thDay
2112323345%75%
2340
11th to 20thDay
221333445%7%66%
2340
21st to endDay
6%413435%5%7%9%53%
2545
August1st to 10thDay
2213424436%69%
2328
11th to 20thDay
211332345%7%70%
2149
21st to endDay
321232345%5%71%
2376
September1st to 10thDay
3313323336%70%
1997
11th to 20thDay
21111122386%
1980
21st to endDay
2212212335%78%
1980
October1st to 10thDay
211211233479%
1980
11th to 20thDay
1111222485%
1900
21st to endDay
1121123484%
1980
November1st to 10thDay
11222333480%
1702
11th to 20thDay
2211213345%76%
1710
21st to endDay
321331235%7%70%
1710
December1st to 10thDay
432443335%6%64%
1710
11th to 20thDay
22246%246%6%7%58%
2169
21st to endDay
6%3243235%7%8%58%
3146
January1st to 10thNight
32124235%5%7%65%
2457
11th to 20thNight
4313323346%68%
2379
21st to endNight
5%323413345%67%
2507
February1st to 10thNight
3312323346%70%
2160
11th to 20thNight
5%31342334468%
2098
21st to endNight
4213324446%68%
1776
March1st to 10thNight
321323346%6%66%
2102
11th to 20thNight
3312322346%73%
1980
21st to endNight
2213323446%70%
2178
April1st to 10thNight
221231335%5%73%
1954
11th to 20thNight
212221223381%
1779
21st to endNight
11111223484%
1657
May1st to 10thNight
1121223483%
1620
11th to 20thNight
11121212385%
1594
21st to endNight
11111112289%
1746
June1st to 10thNight
111111122384%
1620
11th to 20thNight
111112489%
1620
21st to endNight
211111122483%
1620
July1st to 10thNight
111222245%5%75%
1620
11th to 20thNight
321233446%7%66%
1620
21st to endNight
32133246%7%9%60%
1773
August1st to 10thNight
222223446%74%
1611
11th to 20thNight
211232335%7%71%
1749
21st to endNight
2112223447%73%
1980
September1st to 10thNight
1212223445%74%
1962
11th to 20thNight
11111122485%
1980
21st to endNight
111121223482%
1980
October1st to 10thNight
2212213335%75%
1980
11th to 20thNight
1121122486%
2060
21st to endNight
1112212235%83%
2376
November1st to 10thNight
2212222235%78%
2373
11th to 20thNight
2212212335%76%
2470
21st to endNight
4312312345%72%
2470
December1st to 10thNight
431432345%6%66%
2470
11th to 20thNight
44245%34448%58%
3041
21st to endNight
5%31333445%6%62%
4521

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 10thDay
21%3416%34%22%
1709
11th to 20thDay
16%35%12%37%27%
1642
21st to endDay
20%26%15%29%28%
1845
February1st to 10thDay
17%2412%28%38%
1800
11th to 20thDay
19%3312%29%35%
1760
21st to endDay
18%25%12%30%34%
1480
March1st to 10thDay
16%3312%29%36%
1858
11th to 20thDay
16%2312%27%39%
1980
21st to endDay
15%1213%32%36%
2178
April1st to 10thDay
14%2311%29%42%
2002
11th to 20thDay
10%127%28%52%
2132
21st to endDay
8%127%30%52%
2300
May1st to 10thDay
9%239%26%52%
2340
11th to 20thDay
7%235%23%61%
2304
21st to endDay
6%16%23%63%
2530
June1st to 10thDay
8%11318%69%
2340
11th to 20thDay
41312%80%
2340
21st to endDay
9%1249%76%
2340
July1st to 10thDay
12%348%14%59%
2276
11th to 20thDay
17%46%18%25%29%
2271
21st to endDay
25%6%8%19%20%22%
2404
August1st to 10thDay
17%35%13%24%39%
2313
11th to 20thDay
15%5%5%13%29%34%
2149
21st to endDay
15%3411%29%37%
2376
September1st to 10thDay
19%35%11%22%41%
1997
11th to 20thDay
8%127%21%62%
1980
21st to endDay
10%337%17%60%
1980
October1st to 10thDay
11%3311%23%50%
1980
11th to 20thDay
6%127%23%60%
1900
21st to endDay
7%238%24%56%
1980
November1st to 10thDay
11%1211%30%45%
1702
11th to 20thDay
13%2212%26%45%
1710
21st to endDay
17%2411%31%36%
1710
December1st to 10thDay
22%2416%24%32%
1710
11th to 20thDay
24%46%22%25%19%
2168
21st to endDay
22%46%20%31%17%
3146
January1st to 10thNight
19%45%14%30%28%
2457
11th to 20thNight
19%3310%32%33%
2379
21st to endNight
22%2415%22%34%
2507
February1st to 10thNight
17%3312%25%41%
2160
11th to 20thNight
21%2313%22%40%
2099
21st to endNight
19%3410%26%38%
1776
March1st to 10thNight
17%3412%29%36%
2102
11th to 20thNight
15%2312%26%42%
1980
21st to endNight
17%2411%29%37%
2178
April1st to 10thNight
14%2310%29%41%
1954
11th to 20thNight
11%128%26%52%
1779
21st to endNight
7%229%24%56%
1657
May1st to 10thNight
8%128%27%54%
1620
11th to 20thNight
8%126%24%59%
1595
21st to endNight
6%17%26%60%
1746
June1st to 10thNight
8%11318%69%
1620
11th to 20thNight
411212%79%
1620
21st to endNight
8%1247%78%
1620
July1st to 10thNight
12%238%15%59%
1575
11th to 20thNight
16%46%17%26%31%
1566
21st to endNight
18%6%9%21%21%26%
1674
August1st to 10thNight
12%4412%24%45%
1602
11th to 20thNight
14%4314%29%36%
1749
21st to endNight
12%35%12%28%41%
1980
September1st to 10thNight
13%35%13%22%44%
1962
11th to 20thNight
6%227%20%64%
1980
21st to endNight
8%338%17%62%
1980
October1st to 10thNight
13%248%21%52%
1980
11th to 20thNight
7%117%20%64%
2060
21st to endNight
8%138%19%61%
2376
November1st to 10thNight
12%219%25%51%
2373
11th to 20thNight
13%129%25%50%
2470
21st to endNight
17%2311%27%40%
2470
December1st to 10thNight
19%4315%22%36%
2470
11th to 20thNight
26%35%13%27%26%
3041
21st to endNight
23%35%18%33%19%
4521

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 10thDay
7%5%22%37%26%3
270
11th to 20thDay
8%415%37%29%8%
248
21st to endDay
27%24%34%25%8%
327
February1st to 10thDay
5%8%22%28%28%9%
420
11th to 20thDay
6%10%26%35%22%2
415
21st to endDay
413%28%34%18%2
346
March1st to 10thDay
412%25%38%19%2
420
11th to 20thDay
5%8%20%32%29%6%
420
21st to endDay
5%12%27%33%18%5%
462
April1st to 10thDay
46%22%36%24%8%
420
11th to 20thDay
311%30%32%18%6%
412
21st to endDay
28%29%29%22%11%
420
May1st to 10thDay
2420%35%28%10%
423
11th to 20thDay
2322%37%26%11%
448
21st to endDay
15%22%37%23%12%
485
June1st to 10thDay
2414%34%33%13%
450
11th to 20thDay
117%33%32%16%
450
21st to endDay
210%40%35%13%
450
July1st to 10thDay
16%37%39%17%
446
11th to 20thDay
21327%43%24%
444
21st to endDay
41423%44%24%
487
August1st to 10thDay
2431%42%22%
447
11th to 20thDay
3324%42%27%
437
21st to endDay
2226%44%25%
495
September1st to 10thDay
3211%24%41%19%
450
11th to 20thDay
28%35%41%13%
450
21st to endDay
2213%32%36%14%
450
October1st to 10thDay
25%16%35%33%10%
450
11th to 20thDay
1213%36%36%12%
370
21st to endDay
2218%23%42%13%
297
November1st to 10thDay
2313%42%33%9%
270
11th to 20thDay
3313%35%39%8%
270
21st to endDay
1421%38%25%11%
270
December1st to 10thDay
7%212%41%29%9%
270
11th to 20thDay
1217%38%37%4
270
21st to endDay
7%7%21%37%23%5%
297
January1st to 10thNight
4215%43%30%6%
760
11th to 20thNight
4315%40%31%6%
732
21st to endNight
6%418%43%26%3
792
February1st to 10thNight
4415%41%30%6%
720
11th to 20thNight
5%6%19%42%25%4
704
21st to endNight
5%6%23%42%20%5%
592
March1st to 10thNight
45%24%43%21%3
720
11th to 20thNight
4419%36%29%9%
720
21st to endNight
36%23%41%23%5%
792
April1st to 10thNight
3422%41%27%3
720
11th to 20thNight
25%26%39%24%3
711
21st to endNight
15%25%39%27%3
577
May1st to 10thNight
15%22%43%26%3
540
11th to 20thNight
2319%40%33%3
531
21st to endNight
1319%45%27%4
584
June1st to 10thNight
2112%48%34%2
540
11th to 20thNight
113%46%37%3
540
21st to endNight
119%42%43%4
540
July1st to 10thNight
2439%52%3
525
11th to 20thNight
31233%54%6%
522
21st to endNight
2330%55%9%
591
August1st to 10thNight
21332%55%7%
537
11th to 20thNight
31427%54%11%
681
21st to endNight
3325%57%12%
792
September1st to 10thNight
217%30%50%10%
720
11th to 20thNight
117%34%47%10%
720
21st to endNight
1110%36%43%9%
720
October1st to 10thNight
3214%41%36%5%
720
11th to 20thNight
1111%42%39%6%
720
21st to endNight
1312%38%36%11%
792
November1st to 10thNight
2113%42%34%8%
740
11th to 20thNight
2111%40%36%10%
760
21st to endNight
5%216%40%31%7%
760
December1st to 10thNight
5%214%42%33%4
760
11th to 20thNight
6%313%42%32%3
760
21st to endNight
6%317%44%25%5%
836
Page generated at 2024-01-10 17:35:25. Version ac07

Copyright 2024 Attilla Danko


Quartzsite Clear Sky Chart |Charts Home