Farmington
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Farmington clear sky chart from 2005-11-06 to 2024-01-22.

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
35%
24378
22%
74758
13%
24316
45%
24316
26%
46511

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
16%
950
20%
2648
5%
946
30%
946
19%
1771
January11th to 20thNight
14%
950
21%
2494
5%
950
25%
950
17%
1747
January21st to endNight
15%
1000
21%
2600
4%
1000
28%
1000
22%
1779
February1st to 10thNight
14%
892
17%
2332
4%
892
23%
892
18%
1687
February11th to 20thNight
14%
703
20%
2099
5%
700
26%
700
18%
1372
February21st to endNight
17%
592
21%
1776
5%
592
30%
592
17%
1189
March1st to 10thNight
17%
705
20%
2145
6%
705
28%
705
20%
1390
March11th to 20thNight
21%
540
17%
1980
8%
540
33%
540
17%
1309
March21st to endNight
21%
594
14%
2066
7%
594
32%
594
16%
1411
April1st to 10thNight
26%
540
23%
1800
11%
540
43%
540
25%
1022
April11th to 20thNight
31%
533
22%
1775
15%
533
44%
533
23%
1093
April21st to endNight
25%
540
19%
1800
9%
540
40%
540
20%
1160
May1st to 10thNight
34%
540
17%
1779
8%
540
44%
540
25%
1100
May11th to 20thNight
37%
531
20%
1484
13%
531
43%
531
28%
963
May21st to endNight
46%
584
19%
1551
11%
582
52%
582
30%
1027
June1st to 10thNight
59%
540
20%
1440
14%
540
63%
540
37%
876
June11th to 20thNight
62%
540
29%
1440
20%
540
68%
540
50%
790
June21st to endNight
62%
540
26%
1440
17%
540
68%
540
49%
795
July1st to 10thNight
70%
525
21%
1400
18%
525
72%
525
41%
825
July11th to 20thNight
69%
522
23%
1392
19%
522
72%
522
46%
776
July21st to endNight
66%
591
24%
1652
21%
558
71%
558
39%
946
August1st to 10thNight
68%
537
21%
1632
22%
534
71%
534
38%
921
August11th to 20thNight
69%
534
24%
1776
29%
534
72%
534
37%
978
August21st to endNight
68%
594
26%
1980
30%
594
70%
594
37%
1045
September1st to 10thNight
63%
540
27%
1800
27%
540
68%
540
33%
1004
September11th to 20thNight
65%
546
34%
1806
31%
546
71%
546
35%
997
September21st to endNight
53%
720
30%
1980
19%
720
60%
720
39%
1147
October1st to 10thNight
52%
720
29%
2153
21%
720
60%
720
43%
1127
October11th to 20thNight
34%
720
31%
2160
15%
720
49%
720
33%
1229
October21st to endNight
26%
792
25%
2376
12%
792
39%
792
25%
1487
November1st to 10thNight
31%
740
30%
2401
17%
740
48%
740
35%
1279
November11th to 20thNight
29%
760
28%
2470
15%
760
46%
760
26%
1439
November21st to endNight
22%
782
23%
2492
11%
782
36%
782
22%
1560
December1st to 10thNight
22%
950
20%
2660
6%
950
34%
950
22%
1749
December11th to 20thNight
21%
949
21%
3152
7%
948
33%
948
20%
2057
December21st to endNight
16%
1042
12%
4827
4%
1026
29%
1026
10%
3464

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
12%7%35%5%35%5%6%8%43%
74819
Night
12%7%35%5%3445%7%45%
75135
TransparencyDay
40%5%11%25%16%3
74531
Night
40%411%25%18%3
74945
SeeingDay
17%13%29%24%14%4
14425
Night
17%14%30%25%12%2
24382

By Month

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 10thDay
13%9%46%5%35%5%45%40%
1517
11th to 20thDay
15%10%46%5%3445%5%38%
1681
21st to endDay
12%9%47%6%445%45%41%
1791
February1st to 10thDay
16%10%47%6%34445%38%
1625
11th to 20thDay
15%8%47%5%3446%8%36%
1748
21st to endDay
14%12%45%5%345%6%6%38%
1480
March1st to 10thDay
14%9%46%434446%44%
1831
11th to 20thDay
19%10%36%5%345%5%5%35%
1980
21st to endDay
18%11%48%5%35%5%6%6%30%
2290
April1st to 10thDay
9%5%35%5%345%6%8%46%
2160
11th to 20thDay
16%8%35%6%3435%7%40%
2134
21st to endDay
17%7%36%44446%7%38%
2160
May1st to 10thDay
16%6%35%6%35%5%5%8%38%
2178
11th to 20thDay
16%6%35%5%345%6%9%40%
2409
21st to endDay
9%6%36%6%46%6%8%9%37%
2725
June1st to 10thDay
9%425%5%45%5%7%9%45%
2520
11th to 20thDay
5%4245%45%6%7%9%50%
2520
21st to endDay
43245%37%6%8%10%49%
2520
July1st to 10thDay
11%325%5%36%6%7%11%41%
2520
11th to 20thDay
43246%47%6%7%10%48%
2520
21st to endDay
7%5%36%5%35%7%6%9%43%
2564
August1st to 10thDay
7%5%25%5%36%6%7%11%43%
2293
11th to 20thDay
9%5%25%6%46%7%6%10%40%
2125
21st to endDay
8%6%25%5%345%6%9%47%
2376
September1st to 10thDay
12%5%25%4235%6%10%47%
2160
11th to 20thDay
10%425%5%345%6%9%48%
2134
21st to endDay
10%4135%2445%7%54%
1980
October1st to 10thDay
9%5%2442435%7%55%
1803
11th to 20thDay
13%6%24424346%53%
1800
21st to endDay
18%7%24423346%47%
1980
November1st to 10thDay
10%5%24434445%55%
1677
11th to 20thDay
12%8%35%42445%7%46%
1710
21st to endDay
15%8%45%5%34445%43%
1687
December1st to 10thDay
13%9%35%6%34446%41%
1520
11th to 20thDay
12%9%5%7%6%4435%6%38%
1918
21st to endDay
16%13%6%7%7%35%5%5%5%30%
2783
January1st to 10thNight
13%9%46%5%35%45%6%40%
2648
11th to 20thNight
14%10%5%7%5%35%446%37%
2494
21st to endNight
13%9%47%6%3445%6%39%
2600
February1st to 10thNight
18%10%5%7%5%24446%35%
2332
11th to 20thNight
15%7%47%5%3435%5%42%
2098
21st to endNight
15%9%46%6%3435%5%39%
1776
March1st to 10thNight
16%9%35%6%34345%43%
2145
11th to 20thNight
18%9%37%435%445%38%
1980
21st to endNight
18%10%46%5%345%5%6%34%
2066
April1st to 10thNight
10%425%4345%7%6%50%
1800
11th to 20thNight
14%7%35%5%25%5%5%5%45%
1775
21st to endNight
19%6%35%5%35%445%42%
1800
May1st to 10thNight
15%6%244245%48%45%
1779
11th to 20thNight
14%8%334245%5%8%45%
1483
21st to endNight
7%6%36%6%46%6%7%10%39%
1551
June1st to 10thNight
8%5%245%35%5%6%9%49%
1440
11th to 20thNight
6%423225%5%6%9%57%
1440
21st to endNight
3313335%5%7%10%57%
1440
July1st to 10thNight
6%4245%245%6%8%54%
1440
11th to 20thNight
5%41343446%10%55%
1440
21st to endNight
7%424435%5%7%9%49%
1749
August1st to 10thNight
6%4245%35%5%7%9%52%
1642
11th to 20thNight
6%325%435%5%6%9%53%
1776
21st to endNight
7%425%4235%6%8%55%
1980
September1st to 10thNight
11%5%24424347%54%
1800
11th to 20thNight
8%425%5%35%447%54%
1806
21st to endNight
9%42443446%7%55%
1980
October1st to 10thNight
6%314333446%62%
2153
11th to 20thNight
14%5%13423446%54%
2160
21st to endNight
18%8%24423345%47%
2376
November1st to 10thNight
9%5%24423346%59%
2401
11th to 20thNight
13%6%24425%346%50%
2470
21st to endNight
17%8%25%423345%46%
2492
December1st to 10thNight
16%10%45%43445%7%40%
2660
11th to 20thNight
14%9%46%6%34445%41%
3279
21st to endNight
14%15%5%9%7%45%5%5%6%27%
4884

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
46%310%24%14%3
1518
11th to 20thDay
47%310%26%11%2
1681
21st to endDay
45%312%24%14%2
1791
February1st to 10thDay
51%210%23%13%1
1625
11th to 20thDay
46%413%20%13%5%
1758
21st to endDay
47%48%24%11%6%
1480
March1st to 10thDay
43%38%24%17%5%
1831
11th to 20thDay
51%39%19%14%3
1980
21st to endDay
56%411%18%10%1
2290
April1st to 10thDay
37%412%26%20%2
2160
11th to 20thDay
46%310%22%16%4
2134
21st to endDay
47%311%23%14%1
2160
May1st to 10thDay
46%413%25%12%1
2178
11th to 20thDay
42%5%13%23%14%2
2413
21st to endDay
42%8%14%22%12%1
2725
June1st to 10thDay
35%5%14%27%18%1
2520
11th to 20thDay
29%6%12%28%22%4
2520
21st to endDay
28%7%17%26%17%5%
2520
July1st to 10thDay
35%7%15%25%14%4
2451
11th to 20thDay
29%7%16%27%17%3
2445
21st to endDay
37%6%13%30%12%2
2422
August1st to 10thDay
34%7%15%29%14%1
2279
11th to 20thDay
39%6%13%27%13%1
2125
21st to endDay
35%5%15%23%17%5%
2376
September1st to 10thDay
35%412%28%17%4
2160
11th to 20thDay
32%5%9%27%25%2
2134
21st to endDay
29%5%7%30%26%3
1980
October1st to 10thDay
30%410%27%25%4
1803
11th to 20thDay
35%47%26%23%7%
1800
21st to endDay
42%27%26%18%5%
1980
November1st to 10thDay
33%310%27%20%7%
1677
11th to 20thDay
38%48%23%21%6%
1710
21st to endDay
45%38%25%18%1
1687
December1st to 10thDay
45%39%27%14%2
1520
11th to 20thDay
48%38%21%19%2
1915
21st to endDay
58%310%15%11%3
2783
January1st to 10thNight
46%38%23%17%3
2648
11th to 20thNight
49%310%24%13%1
2494
21st to endNight
46%310%25%15%2
2600
February1st to 10thNight
52%38%22%13%2
2332
11th to 20thNight
45%310%21%18%3
2099
21st to endNight
48%39%22%15%4
1776
March1st to 10thNight
45%39%20%18%5%
2145
11th to 20thNight
49%410%20%14%3
1980
21st to endNight
51%413%22%9%1
2066
April1st to 10thNight
34%5%12%26%21%3
1800
11th to 20thNight
41%410%23%18%4
1775
21st to endNight
45%48%26%15%2
1800
May1st to 10thNight
39%5%14%24%16%2
1779
11th to 20thNight
39%7%12%23%17%2
1484
21st to endNight
39%6%16%20%16%2
1552
June1st to 10thNight
32%6%14%27%20%2
1440
11th to 20thNight
23%413%33%23%4
1440
21st to endNight
22%5%17%30%18%7%
1440
July1st to 10thNight
29%5%17%28%16%5%
1400
11th to 20thNight
26%417%29%20%5%
1392
21st to endNight
30%5%16%30%17%1
1652
August1st to 10thNight
28%7%17%31%15%2
1632
11th to 20thNight
28%7%14%28%22%2
1776
21st to endNight
28%5%13%28%22%5%
1980
September1st to 10thNight
33%49%30%18%6%
1800
11th to 20thNight
31%49%29%24%2
1806
21st to endNight
29%48%25%28%4
1980
October1st to 10thNight
24%411%28%28%5%
2153
11th to 20thNight
33%28%26%24%7%
2160
21st to endNight
41%37%23%21%5%
2376
November1st to 10thNight
29%311%28%23%6%
2401
11th to 20thNight
37%37%24%24%6%
2470
21st to endNight
43%38%24%20%2
2492
December1st to 10thNight
44%312%24%15%2
2660
11th to 20thNight
45%49%25%17%1
3281
21st to endNight
58%39%18%10%2
4884

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
31%21%33%11%3
270
11th to 20thDay
31%29%31%9%
270
21st to endDay
21%34%33%10%1
267
February1st to 10thDay
26%27%37%10%1
240
11th to 20thDay
32%28%31%7%2
240
21st to endDay
32%27%33%7%11
198
March1st to 10thDay
22%30%36%11%1
240
11th to 20thDay
33%23%33%8%3
240
21st to endDay
30%22%33%13%2
376
April1st to 10thDay
20%21%38%17%4
420
11th to 20thDay
26%20%29%19%5%1
412
21st to endDay
23%18%37%16%5%1
420
May1st to 10thDay
21%20%36%17%6%1
423
11th to 20thDay
19%15%32%21%10%3
555
21st to endDay
11%10%36%25%13%5%
679
June1st to 10thDay
11%6%26%29%23%5%
630
11th to 20thDay
7%5%28%37%20%4
630
21st to endDay
5%7%32%34%17%5%
630
July1st to 10thDay
11%319%28%29%10%
621
11th to 20thDay
5%321%41%24%6%
618
21st to endDay
8%420%36%26%6%
684
August1st to 10thDay
9%317%39%24%7%
591
11th to 20thDay
10%421%31%27%6%
439
21st to endDay
11%317%31%28%11%
495
September1st to 10thDay
12%5%19%34%24%6%
450
11th to 20thDay
8%420%32%26%10%
450
21st to endDay
12%9%24%26%20%8%
450
October1st to 10thDay
13%10%34%33%7%3
273
11th to 20thDay
22%16%40%18%4
270
21st to endDay
30%22%30%16%2
297
November1st to 10thDay
14%17%39%23%6%1
270
11th to 20thDay
24%21%31%19%6%
270
21st to endDay
28%17%34%16%41
270
December1st to 10thDay
19%24%35%13%6%2
270
11th to 20thDay
27%23%32%15%3
270
21st to endDay
30%24%34%10%2
297
January1st to 10thNight
22%23%35%17%3
950
11th to 20thNight
24%28%31%14%3
950
21st to endNight
19%25%38%17%1
1000
February1st to 10thNight
25%23%35%15%1
892
11th to 20thNight
22%24%37%15%2
703
21st to endNight
26%23%32%18%1
592
March1st to 10thNight
26%18%36%18%2
705
11th to 20thNight
23%16%38%21%3
540
21st to endNight
26%16%32%21%4
594
April1st to 10thNight
13%21%38%25%3
540
11th to 20thNight
20%16%30%25%8%1
533
21st to endNight
21%14%37%21%7%
540
May1st to 10thNight
16%11%36%28%8%1
540
11th to 20thNight
19%6%36%26%13%1
531
21st to endNight
12%6%29%33%17%4
584
June1st to 10thNight
10%5%21%38%24%2
540
11th to 20thNight
8%223%45%20%1
540
21st to endNight
4328%39%24%2
540
July1st to 10thNight
8%212%37%33%8%
525
11th to 20thNight
6%216%42%30%4
522
21st to endNight
8%117%39%32%3
591
August1st to 10thNight
7%115%38%35%4
537
11th to 20thNight
7%115%39%34%4
534
21st to endNight
7%215%35%34%7%
594
September1st to 10thNight
13%316%35%29%5%
540
11th to 20thNight
10%216%35%31%6%
546
21st to endNight
11%6%25%27%26%5%
720
October1st to 10thNight
8%6%30%31%21%4
720
11th to 20thNight
16%14%33%24%11%1
720
21st to endNight
24%16%32%21%6%
792
November1st to 10thNight
12%12%41%24%10%
740
11th to 20thNight
20%17%33%24%6%
760
21st to endNight
24%18%34%19%5%
782
December1st to 10thNight
22%18%36%20%4
950
11th to 20thNight
23%16%36%21%3
950
21st to endNight
25%21%34%17%2
1045
Page generated at 2024-01-19 08:28:30. Version ac07

Copyright 2024 Attilla Danko


Farmington Clear Sky Chart |Charts Home