Navajo Flats
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Navajo Flats clear sky chart from 2005-11-06 to 2024-02-20.

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
73%
24176
33%
79961
30%
24092
78%
24092
45%
39758

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
53%
751
28%
4182
22%
736
59%
736
20%
2050
January11th to 20thNight
61%
749
28%
4011
27%
740
68%
740
21%
2186
January21st to endNight
59%
830
19%
4355
28%
814
65%
814
18%
2636
February1st to 10thNight
60%
760
30%
2372
29%
760
66%
760
36%
1316
February11th to 20thNight
63%
738
32%
2212
30%
738
70%
738
41%
1184
February21st to endNight
56%
592
28%
1776
25%
592
64%
592
36%
1007
March1st to 10thNight
58%
720
22%
2134
19%
720
63%
720
33%
1272
March11th to 20thNight
63%
720
26%
1980
23%
720
68%
720
38%
1169
March21st to endNight
60%
792
26%
2064
16%
792
66%
792
43%
1186
April1st to 10thNight
66%
720
29%
1800
18%
720
71%
720
48%
1022
April11th to 20thNight
62%
711
34%
1779
17%
711
69%
711
54%
945
April21st to endNight
68%
720
33%
1800
16%
720
72%
720
57%
947
May1st to 10thNight
75%
720
32%
1800
18%
720
78%
720
65%
884
May11th to 20thNight
78%
602
37%
1666
27%
602
80%
602
66%
759
May21st to endNight
79%
406
38%
1570
38%
406
86%
406
58%
574
June1st to 10thNight
84%
360
37%
1440
42%
360
88%
360
60%
505
June11th to 20thNight
89%
360
42%
1440
48%
360
93%
360
76%
433
June21st to endNight
94%
360
43%
1440
54%
360
95%
360
81%
425
July1st to 10thNight
98%
350
42%
1400
51%
350
98%
350
80%
411
July11th to 20thNight
95%
462
40%
1506
39%
462
95%
462
78%
538
July21st to endNight
93%
591
42%
1674
36%
558
94%
558
71%
694
August1st to 10thNight
92%
662
40%
1727
28%
659
92%
659
79%
757
August11th to 20thNight
94%
712
43%
1780
27%
712
94%
712
83%
790
August21st to endNight
96%
792
47%
1980
32%
792
96%
792
87%
853
September1st to 10thNight
92%
720
46%
1800
35%
720
93%
720
81%
812
September11th to 20thNight
90%
720
49%
1818
41%
720
92%
720
77%
826
September21st to endNight
88%
720
46%
1980
44%
720
91%
720
78%
835
October1st to 10thNight
84%
720
37%
2124
39%
720
88%
720
66%
932
October11th to 20thNight
80%
720
39%
2160
41%
720
84%
720
56%
1000
October21st to endNight
80%
792
44%
2376
45%
792
84%
792
60%
1056
November1st to 10thNight
74%
740
38%
2321
37%
740
79%
740
52%
1081
November11th to 20thNight
72%
760
35%
2470
34%
760
78%
760
49%
1153
November21st to endNight
66%
760
31%
2470
29%
760
72%
760
40%
1290
December1st to 10thNight
63%
760
30%
2538
28%
760
69%
760
36%
1354
December11th to 20thNight
58%
760
22%
3225
25%
759
64%
759
20%
2074
December21st to endNight
53%
824
15%
4791
23%
817
61%
817
16%
2802

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
4323323446%65%
78567
Night
4424423446%63%
80646
TransparencyDay
21%36%19%28%23%
78284
Night
24%37%19%25%22%
80450
SeeingDay
6%9%23%33%23%7%
14508
Night
6%412%35%36%8%
24219

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
6%5%25%5%35%6%6%7%51%
2649
11th to 20thDay
8%8%35%5%35%6%6%8%44%
2860
21st to endDay
10%9%38%5%35%6%6%8%37%
3146
February1st to 10thDay
11%7%24424346%54%
1805
11th to 20thDay
6%5%35%5%3446%8%51%
1841
21st to endDay
8%7%36%5%245%46%50%
1480
March1st to 10thDay
8%7%36%6%46%6%6%7%42%
1824
11th to 20thDay
9%5%246%445%5%10%46%
1980
21st to endDay
5%5%245%345%47%54%
2290
April1st to 10thDay
7%5%2443445%7%55%
2160
11th to 20thDay
5%3244245%5%8%60%
2129
21st to endDay
322332335%7%66%
2160
May1st to 10thDay
321331345%7%70%
2160
11th to 20thDay
221122335%6%72%
2229
21st to endDay
211332335%6%71%
2701
June1st to 10thDay
221232335%6%72%
2520
11th to 20thDay
111122388%
2520
21st to endDay
1121222387%
2520
July1st to 10thDay
1111113487%
2520
11th to 20thDay
2111212225%81%
2398
21st to endDay
1112222336%77%
2546
August1st to 10thDay
11211223483%
2203
11th to 20thDay
1111121389%
2122
21st to endDay
11111122486%
2376
September1st to 10thDay
11111123487%
2160
11th to 20thDay
11111222485%
2140
21st to endDay
1111222245%80%
1980
October1st to 10thDay
2113223436%73%
1832
11th to 20thDay
1223324436%72%
1800
21st to endDay
2213423446%71%
1980
November1st to 10thDay
442342336%7%64%
1756
11th to 20thDay
33144336%46%64%
1710
21st to endDay
6%3244245%5%7%57%
1710
December1st to 10thDay
5%435%5%45%6%5%8%51%
1638
11th to 20thDay
11%9%48%5%45%6%5%6%37%
1928
21st to endDay
10%8%36%7%45%6%6%8%39%
2794
January1st to 10thNight
7%8%26%5%3445%7%49%
4284
11th to 20thNight
6%8%37%6%445%6%9%44%
4110
21st to endNight
11%11%36%5%345%5%8%39%
4521
February1st to 10thNight
7%6%34425%35%5%55%
2372
11th to 20thNight
5%324435%5%5%8%57%
2211
21st to endNight
7%6%25%434346%56%
1776
March1st to 10thNight
6%6%25%6%35%6%6%8%47%
2134
11th to 20thNight
5%5%345%35%5%6%8%51%
1980
21st to endNight
6%5%2442345%7%57%
2064
April1st to 10thNight
4324434448%60%
1800
11th to 20thNight
4423322345%68%
1779
21st to endNight
3222324448%67%
1800
May1st to 10thNight
221222335%8%72%
1800
11th to 20thNight
1212323338%75%
1665
21st to endNight
111212235%6%75%
1570
June1st to 10thNight
11221235%6%77%
1440
11th to 20thNight
1112125%87%
1440
21st to endNight
111112389%
1440
July1st to 10thNight
11122488%
1440
11th to 20thNight
1111111235%84%
1556
21st to endNight
112312335%78%
1773
August1st to 10thNight
111121123385%
1736
11th to 20thNight
1111122486%
1780
21st to endNight
111112389%
1980
September1st to 10thNight
11111222486%
1800
11th to 20thNight
11111222384%
1818
21st to endNight
11221232484%
1980
October1st to 10thNight
2212222346%75%
2124
11th to 20thNight
2313323336%71%
2160
21st to endNight
2313223235%74%
2376
November1st to 10thNight
331332345%7%67%
2321
11th to 20thNight
231442445%6%65%
2470
21st to endNight
44244345%6%8%55%
2470
December1st to 10thNight
6%5%24435%46%9%52%
2538
11th to 20thNight
10%8%48%7%445%6%7%38%
3276
21st to endNight
9%6%37%7%46%5%6%8%39%
4862

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
32%38%35%17%5%
2649
11th to 20thDay
38%210%23%17%10%
2860
21st to endDay
46%29%21%14%9%
3146
February1st to 10thDay
33%35%19%23%17%
1805
11th to 20thDay
32%46%23%25%11%
1851
21st to endDay
36%38%20%26%7%
1480
March1st to 10thDay
40%49%18%20%9%
1824
11th to 20thDay
34%5%10%21%21%8%
1980
21st to endDay
31%311%29%19%8%
2290
April1st to 10thDay
30%411%26%21%10%
2160
11th to 20thDay
24%311%27%25%10%
2132
21st to endDay
20%39%30%30%8%
2160
May1st to 10thDay
15%39%23%37%13%
2160
11th to 20thDay
14%35%30%36%13%
2232
21st to endDay
14%48%34%33%7%
2701
June1st to 10thDay
15%29%21%36%18%
2520
11th to 20thDay
5%1415%42%33%
2520
21st to endDay
7%128%35%47%
2520
July1st to 10thDay
5%117%31%55%
2451
11th to 20thDay
9%2310%30%46%
2325
21st to endDay
11%3313%30%41%
2405
August1st to 10thDay
8%219%30%50%
2187
11th to 20thDay
5%111%37%46%
2122
21st to endDay
5%110%37%46%
2376
September1st to 10thDay
5%129%32%50%
2160
11th to 20thDay
7%1117%42%31%
2140
21st to endDay
9%1117%41%29%
1980
October1st to 10thDay
14%2422%24%33%
1832
11th to 20thDay
15%45%17%30%29%
1800
21st to endDay
16%3415%33%29%
1980
November1st to 10thDay
21%27%21%29%21%
1756
11th to 20thDay
22%39%22%25%20%
1710
21st to endDay
25%47%16%24%23%
1710
December1st to 10thDay
32%47%19%20%19%
1638
11th to 20thDay
48%38%16%16%9%
1928
21st to endDay
44%28%24%17%5%
2794
January1st to 10thNight
36%29%28%21%4
4284
11th to 20thNight
39%29%27%12%10%
4110
21st to endNight
45%28%22%14%9%
4521
February1st to 10thNight
31%47%18%25%16%
2372
11th to 20thNight
27%37%22%28%12%
2212
21st to endNight
31%48%23%27%8%
1776
March1st to 10thNight
33%6%11%23%18%8%
2134
11th to 20thNight
31%411%21%25%8%
1980
21st to endNight
26%414%26%23%7%
2064
April1st to 10thNight
23%5%14%27%19%11%
1800
11th to 20thNight
20%211%28%29%10%
1779
21st to endNight
17%410%28%32%9%
1800
May1st to 10thNight
12%411%26%33%15%
1800
11th to 20thNight
12%26%28%37%15%
1666
21st to endNight
11%37%33%34%12%
1570
June1st to 10thNight
11%39%21%34%22%
1440
11th to 20thNight
6%1414%37%37%
1440
21st to endNight
4127%32%54%
1440
July1st to 10thNight
4219%25%60%
1400
11th to 20thNight
7%1210%26%55%
1506
21st to endNight
9%318%28%51%
1674
August1st to 10thNight
8%116%24%60%
1727
11th to 20thNight
5%27%32%54%
1780
21st to endNight
5%16%33%55%
1980
September1st to 10thNight
7%126%27%57%
1800
11th to 20thNight
8%2212%37%39%
1818
21st to endNight
7%2115%43%32%
1980
October1st to 10thNight
13%2420%26%35%
2124
11th to 20thNight
17%35%15%31%29%
2160
21st to endNight
15%2318%33%29%
2376
November1st to 10thNight
19%35%22%28%23%
2321
11th to 20thNight
20%39%21%25%21%
2470
21st to endNight
26%48%17%24%20%
2470
December1st to 10thNight
29%48%19%21%19%
2538
11th to 20thNight
46%49%15%17%9%
3276
21st to endNight
45%210%20%17%6%
4862

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
20%13%34%23%9%1
251
11th to 20thDay
14%15%28%29%12%2
370
21st to endDay
13%14%33%23%15%2
407
February1st to 10thDay
13%15%27%29%13%3
415
11th to 20thDay
12%17%29%29%13%2
452
21st to endDay
13%18%32%25%10%3
346
March1st to 10thDay
18%15%31%26%10%
420
11th to 20thDay
14%15%28%30%12%1
420
21st to endDay
13%19%31%27%9%2
462
April1st to 10thDay
13%11%30%26%17%2
420
11th to 20thDay
9%14%32%26%15%3
412
21st to endDay
413%32%30%16%5%
420
May1st to 10thDay
8%10%30%30%17%5%
423
11th to 20thDay
29%29%33%22%4
448
21st to endDay
313%23%34%20%7%
485
June1st to 10thDay
36%21%35%26%10%
450
11th to 20thDay
16%21%39%24%9%
450
21st to endDay
316%36%30%14%
450
July1st to 10thDay
110%40%35%14%
446
11th to 20thDay
116%36%35%21%
444
21st to endDay
17%35%39%17%
487
August1st to 10thDay
2115%39%30%14%
447
11th to 20thDay
118%38%35%17%
437
21st to endDay
17%35%41%15%
495
September1st to 10thDay
1312%37%34%13%
450
11th to 20thDay
2417%40%32%6%
450
21st to endDay
5%16%40%32%6%
450
October1st to 10thDay
26%25%37%26%4
450
11th to 20thDay
28%24%37%25%4
450
21st to endDay
37%23%35%26%5%
495
November1st to 10thDay
6%8%24%32%28%3
352
11th to 20thDay
49%27%36%21%4
270
21st to endDay
10%7%24%34%20%4
270
December1st to 10thDay
6%14%28%41%11%1
236
11th to 20thDay
11%14%26%27%17%5%
180
21st to endDay
16%14%31%25%9%4
198
January1st to 10thNight
14%6%17%35%22%6%
760
11th to 20thNight
10%417%42%23%5%
760
21st to endNight
13%5%17%42%20%4
836
February1st to 10thNight
13%8%13%38%24%5%
760
11th to 20thNight
8%8%17%39%24%5%
742
21st to endNight
12%8%18%42%17%4
592
March1st to 10thNight
9%8%18%43%20%3
720
11th to 20thNight
9%5%15%38%28%6%
720
21st to endNight
9%8%17%37%25%3
792
April1st to 10thNight
7%6%15%44%25%3
720
11th to 20thNight
7%7%20%32%30%5%
711
21st to endNight
46%17%36%30%7%
720
May1st to 10thNight
3414%38%33%7%
720
11th to 20thNight
2414%35%39%6%
602
21st to endNight
25%11%36%37%8%
407
June1st to 10thNight
238%34%49%5%
360
11th to 20thNight
8%33%52%7%
360
21st to endNight
11430%56%9%
360
July1st to 10thNight
121%69%9%
350
11th to 20thNight
211%64%23%
462
21st to endNight
1112%61%25%
591
August1st to 10thNight
1224%57%16%
662
11th to 20thNight
120%64%14%
712
21st to endNight
1118%64%17%
792
September1st to 10thNight
11423%58%13%
720
11th to 20thNight
21435%48%11%
720
21st to endNight
117%31%51%10%
720
October1st to 10thNight
318%40%41%7%
720
11th to 20thNight
439%41%37%7%
720
21st to endNight
4210%40%36%9%
792
November1st to 10thNight
4413%38%33%8%
740
11th to 20thNight
4313%46%27%6%
760
21st to endNight
5%5%16%43%26%6%
760
December1st to 10thNight
11%5%15%41%25%4
760
11th to 20thNight
12%417%44%20%3
760
21st to endNight
12%7%19%41%18%4
836
Page generated at 2024-02-17 03:28:39. Version ac07

Copyright 2024 Attilla Danko


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