Navajo Peak
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Navajo Peak clear sky chart from 2005-11-05 to 2017-09-24.

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%
15811
24%
46984
17%
15768
55%
15768
29%
28023

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
50%
777
26%
2383
22%
772
57%
772
32%
1316
January16th to endNight
44%
768
28%
2496
22%
768
54%
768
27%
1436
February1st to 15thNight
42%
700
22%
2270
19%
700
49%
700
25%
1322
February16th to endNight
34%
632
27%
1894
14%
632
48%
632
23%
1191
March1st to 15thNight
42%
720
26%
2019
15%
720
51%
720
31%
1211
March16th to endNight
40%
735
27%
2079
15%
735
49%
735
33%
1215
April1st to 15thNight
30%
539
21%
1798
14%
539
39%
539
21%
1102
April16th to endNight
32%
540
25%
1800
14%
540
48%
540
24%
1029
May1st to 15thNight
36%
540
21%
1731
13%
540
47%
540
24%
1031
May16th to endNight
40%
563
24%
1513
12%
561
50%
561
30%
915
June1st to 15thNight
51%
540
28%
1440
16%
540
60%
540
41%
778
June16th to endNight
58%
540
26%
1440
17%
540
65%
540
41%
785
July1st to 15thNight
59%
510
12%
1401
10%
510
60%
510
22%
969
July16th to endNight
63%
564
12%
1593
12%
531
67%
531
21%
1099
August1st to 15thNight
66%
539
14%
1653
14%
536
67%
536
23%
1086
August16th to endNight
66%
573
19%
1910
20%
573
69%
573
25%
1214
September1st to 15thNight
60%
540
19%
1800
19%
540
63%
540
22%
1155
September16th to endNight
62%
580
33%
1880
24%
580
71%
580
35%
1007
October1st to 15thNight
53%
660
29%
1980
20%
660
60%
660
36%
1125
October16th to endNight
57%
704
34%
2112
20%
704
67%
704
39%
1117
November1st to 15thNight
55%
787
33%
2187
24%
787
59%
787
39%
1195
November16th to endNight
47%
900
32%
2397
17%
900
57%
900
38%
1357
December1st to 15thNight
39%
900
20%
2520
12%
900
45%
900
27%
1538
December16th to endNight
35%
960
19%
2688
13%
960
39%
960
20%
1830

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
8%8%24424446%48%
47941
Night
7%8%24323346%53%
47173
TransparencyDay
36%6%9%20%19%5%
47629
Night
32%6%10%21%21%6%
46985
SeeingDay
13%22%24%22%13%3
5667
Night
10%19%17%29%19%3
15815

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
6%11%4441223455%
1565
16th to endDay
7%12%35%212235%53%
1728
February1st to 15thDay
413%5%7%222225%50%
1591
16th to endDay
7%16%5%6%324336%40%
1580
March1st to 15thDay
5%13%5%5%313236%49%
1938
16th to endDay
8%11%44313336%48%
2145
April1st to 15thDay
8%12%25%4235%47%43%
2150
16th to endDay
8%12%23324446%46%
2160
May1st to 15thDay
8%10%35%42445%6%42%
2217
16th to endDay
8%7%24424445%51%
2597
June1st to 15thDay
5%3133235%5%6%58%
2520
16th to endDay
221332445%6%62%
2520
July1st to 15thDay
7%5%26%5%47%7%6%8%37%
2473
16th to endDay
8%5%26%8%5%8%7%7%8%29%
2467
August1st to 15thDay
12%6%36%6%46%6%5%5%36%
2298
16th to endDay
11%6%26%7%35%5%6%7%38%
2292
September1st to 15thDay
13%6%26%5%25%5%46%40%
2160
16th to endDay
12%41341323456%
1934
October1st to 15thDay
15%5%12313335%54%
1650
16th to endDay
9%6%23211225%61%
1760
November1st to 15thDay
7%6%12212235%62%
1657
16th to endDay
5%7%32222225%63%
1563
December1st to 15thDay
7%13%35%22236%51%
1440
16th to endDay
7%16%48%212235%44%
1536
January1st to 15thNight
411%1421223460%
2383
16th to endNight
7%10%34311235%56%
2496
February1st to 15thNight
413%45%212226%54%
2260
16th to endNight
6%17%3421223450%
1894
March1st to 15thNight
6%9%34313246%54%
2019
16th to endNight
9%9%23212346%55%
2079
April1st to 15thNight
10%12%3432334447%
1798
16th to endNight
10%8%1332333454%
1800
May1st to 15thNight
10%7%23323436%51%
1730
16th to endNight
6%6%1332435%6%54%
1513
June1st to 15thNight
3312323345%65%
1440
16th to endNight
311232446%7%62%
1440
July1st to 15thNight
6%426%6%38%7%9%9%35%
1484
16th to endNight
5%4246%46%8%10%9%35%
1701
August1st to 15thNight
7%425%5%36%7%8%9%39%
1662
16th to endNight
7%425%5%45%6%6%8%42%
1910
September1st to 15thNight
9%5%146%46%5%7%6%40%
1800
16th to endNight
8%413312245%61%
1880
October1st to 15thNight
12%41331233459%
1980
16th to endNight
7%5%13212235%64%
2112
November1st to 15thNight
7%6%11212346%62%
2187
16th to endNight
7%9%2211222464%
2397
December1st to 15thNight
8%10%25%21223454%
2520
16th to endNight
8%13%49%323336%42%
2688

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
35%212%30%16%2
1566
16th to endDay
35%412%24%19%4
1728
February1st to 15thDay
40%412%23%14%4
1591
16th to endDay
45%46%19%21%2
1580
March1st to 15thDay
38%39%23%20%3
1938
16th to endDay
37%48%26%19%2
2145
April1st to 15thDay
40%5%9%22%18%4
2150
16th to endDay
38%5%7%21%22%3
2160
May1st to 15thDay
41%8%7%21%19%2
2217
16th to endDay
34%5%9%19%24%6%
2600
June1st to 15thDay
24%6%8%20%24%15%
2520
16th to endDay
22%5%7%18%28%17%
2520
July1st to 15thDay
40%12%13%12%13%8%
2327
16th to endDay
47%15%16%14%5%1
2312
August1st to 15thDay
47%10%10%13%12%6%
2283
16th to endDay
44%10%11%16%13%3
2292
September1st to 15thDay
43%9%9%16%15%5%
2160
16th to endDay
32%5%5%19%31%5%
1934
October1st to 15thDay
34%4424%24%6%
1650
16th to endDay
27%46%25%31%5%
1760
November1st to 15thDay
26%49%22%30%6%
1657
16th to endDay
25%29%31%23%7%
1563
December1st to 15thDay
35%416%25%16%1
1440
16th to endDay
46%314%20%13%2
1536
January1st to 15thNight
29%412%26%24%3
2383
16th to endNight
33%48%27%20%5%
2496
February1st to 15thNight
34%413%25%16%5%
2270
16th to endNight
39%5%7%20%24%3
1894
March1st to 15thNight
32%49%25%22%4
2019
16th to endNight
30%47%27%24%5%
2079
April1st to 15thNight
40%47%18%23%5%
1798
16th to endNight
33%5%9%23%22%5%
1800
May1st to 15thNight
34%6%7%22%23%4
1731
16th to endNight
31%6%10%20%23%7%
1514
June1st to 15thNight
22%48%18%25%20%
1440
16th to endNight
20%6%10%13%29%19%
1440
July1st to 15thNight
40%11%15%11%8%12%
1401
16th to endNight
37%16%20%16%6%1
1593
August1st to 15thNight
36%13%16%14%12%6%
1653
16th to endNight
36%10%16%19%13%3
1910
September1st to 15thNight
39%9%14%15%14%6%
1800
16th to endNight
26%5%7%21%32%7%
1880
October1st to 15thNight
29%47%22%26%8%
1980
16th to endNight
23%5%5%23%36%5%
2112
November1st to 15thNight
24%5%8%24%31%6%
2187
16th to endNight
27%37%28%25%8%
2397
December1st to 15thNight
33%5%14%26%18%1
2520
16th to endNight
45%412%18%13%4
2688

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
34%12%21%18%13%
90
16th to endDay
18%12%34%20%9%4
96
February1st to 15thDay
13%18%26%28%12%
90
16th to endDay
16%25%29%17%11%
81
March1st to 15thDay
14%32%28%20%3
228
16th to endDay
17%42%27%8%4
288
April1st to 15thDay
17%40%23%11%41
269
16th to endDay
22%43%23%8%1
270
May1st to 15thDay
18%39%26%11%3
288
16th to endDay
15%27%25%19%11%1
498
June1st to 15thDay
7%22%25%23%17%3
495
16th to endDay
220%23%24%20%8%
495
July1st to 15thDay
9%13%18%25%25%6%
431
16th to endDay
11%11%17%31%22%4
327
August1st to 15thDay
14%10%26%31%13%3
315
16th to endDay
12%11%21%30%21%2
332
September1st to 15thDay
12%12%34%22%14%4
315
16th to endDay
15%14%29%28%5%5%
207
October1st to 15thDay
6%17%23%31%15%5%
90
16th to endDay
22%14%25%19%15%2
96
November1st to 15thDay
11%16%21%25%23%2
90
16th to endDay
22%18%25%24%8%
90
December1st to 15thDay
16%20%28%31%21
90
16th to endDay
21%15%32%25%5%
96
January1st to 15thNight
9%20%14%35%17%3
777
16th to endNight
12%20%18%30%14%2
768
February1st to 15thNight
10%22%20%33%11%1
704
16th to endNight
12%22%27%30%7%
632
March1st to 15thNight
8%24%21%32%11%2
720
16th to endNight
10%23%23%31%9%
735
April1st to 15thNight
13%24%27%26%6%
539
16th to endNight
12%25%27%23%10%1
540
May1st to 15thNight
12%22%25%27%11%1
540
16th to endNight
9%22%23%28%14%1
563
June1st to 15thNight
420%20%35%18%1
540
16th to endNight
319%13%33%27%3
540
July1st to 15thNight
7%12%9%30%34%5%
510
16th to endNight
416%320%45%8%
564
August1st to 15thNight
7%10%5%22%45%8%
539
16th to endNight
7%8%8%25%39%10%
573
September1st to 15thNight
10%9%10%30%33%7%
540
16th to endNight
8%10%13%30%27%10%
580
October1st to 15thNight
12%11%18%30%20%6%
660
16th to endNight
9%11%15%31%23%7%
704
November1st to 15thNight
10%18%13%32%22%3
787
16th to endNight
10%21%18%28%17%4
900
December1st to 15thNight
13%23%20%30%10%1
900
16th to endNight
13%23%20%28%10%1
960
Page generated at 2017-09-25 07:02:29. Version ac04

Copyright 2017 A. Danko


Navajo Peak Clear Sky Chart | Charts Home