Torrington
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Torrington clear sky chart from 2005-11-05 to 2017-12-20.

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
46%
16450
24%
48046
14%
16409
54%
16409
37%
27698

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
38%
899
23%
2506
13%
895
46%
895
35%
1484
January16th to endNight
34%
903
26%
2631
12%
903
47%
903
35%
1517
February1st to 15thNight
35%
696
18%
2250
10%
696
45%
696
29%
1351
February16th to endNight
35%
632
22%
1894
10%
632
47%
632
31%
1147
March1st to 15thNight
40%
720
22%
2160
11%
720
50%
720
36%
1221
March16th to endNight
40%
650
21%
1997
13%
650
49%
650
31%
1215
April1st to 15thNight
35%
539
18%
1798
11%
539
46%
539
27%
1070
April16th to endNight
38%
540
17%
1767
13%
540
46%
540
24%
1114
May1st to 15thNight
45%
540
20%
1542
12%
540
52%
540
30%
971
May16th to endNight
49%
562
17%
1498
12%
561
52%
561
31%
970
June1st to 15thNight
48%
540
15%
1440
8%
540
52%
540
36%
876
June16th to endNight
58%
540
22%
1440
12%
540
63%
540
54%
747
July1st to 15thNight
66%
510
18%
1360
13%
510
68%
510
43%
789
July16th to endNight
71%
564
27%
1416
20%
531
72%
531
52%
742
August1st to 15thNight
69%
539
21%
1576
18%
536
72%
536
42%
859
August16th to endNight
68%
573
29%
1910
30%
573
74%
573
42%
966
September1st to 15thNight
61%
540
26%
1800
24%
540
68%
540
37%
969
September16th to endNight
61%
537
35%
1955
32%
537
70%
537
43%
912
October1st to 15thNight
49%
678
24%
2118
16%
678
56%
678
35%
1207
October16th to endNight
50%
864
32%
2400
16%
864
60%
864
43%
1346
November1st to 15thNight
46%
950
28%
2470
14%
950
53%
950
43%
1419
November16th to endNight
47%
975
31%
2633
15%
975
58%
975
44%
1485
December1st to 15thNight
33%
975
18%
2730
9%
975
42%
975
33%
1668
December16th to endNight
37%
984
23%
2755
11%
984
47%
984
34%
1653

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
7%42432445%8%52%
48810
Night
7%5%2442445%7%53%
48218
Cloud CoverDay
6%42442445%8%52%
48808
Night
6%5%2442445%7%52%
48218
TransparencyDay
28%5%13%26%18%6%
48484
Night
29%5%14%27%17%5%
48046
SeeingDay
9%6%26%30%20%4
6260
Night
9%5%33%39%11%
16460

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
36%25%5%3445%8%50%
1432
16th to endDay
45%2442336%6%56%
1602
February1st to 15thDay
5%7%46%4245%47%46%
1611
16th to endDay
6%7%36%42345%8%47%
1580
March1st to 15thDay
6%5%2442345%9%52%
1800
16th to endDay
8%4244245%5%7%48%
2224
April1st to 15thDay
9%5%35%4235%5%7%46%
2150
16th to endDay
14%6%2443445%8%41%
2192
May1st to 15thDay
13%5%1443445%6%45%
2408
16th to endDay
11%416%425%6%5%10%39%
2616
June1st to 15thDay
8%213425%46%9%50%
2520
16th to endDay
311222445%8%64%
2520
July1st to 15thDay
5%21333445%10%54%
2520
16th to endDay
5%2133245%6%9%56%
2656
August1st to 15thDay
5%2124345%7%10%52%
2371
16th to endDay
421322345%7%61%
2292
September1st to 15thDay
8%31231335%6%59%
2160
16th to endDay
6%313212347%63%
2004
October1st to 15thDay
12%423314445%53%
1839
16th to endDay
6%21322345%7%60%
1812
November1st to 15thDay
5%41333435%9%54%
1718
16th to endDay
441332335%8%59%
1655
December1st to 15thDay
5%5%343145%6%8%50%
1560
16th to endDay
6%7%23425%45%8%48%
1568
January1st to 15thNight
46%244245%5%8%50%
2506
16th to endNight
45%25%415%5%47%53%
2631
February1st to 15thNight
5%7%25%5%245%5%8%47%
2240
16th to endNight
6%7%25%42446%6%49%
1894
March1st to 15thNight
5%6%2432346%8%51%
2160
16th to endNight
7%8%25%42345%8%47%
1997
April1st to 15thNight
9%5%24434446%49%
1798
16th to endNight
16%5%25%4245%5%5%42%
1767
May1st to 15thNight
13%325%42445%6%46%
1541
16th to endNight
12%42443446%9%44%
1497
June1st to 15thNight
9%41432446%8%49%
1440
16th to endNight
31223446%8%61%
1440
July1st to 15thNight
5%2144345%7%7%52%
1440
16th to endNight
3213224448%62%
1512
August1st to 15thNight
33134345%8%10%52%
1584
16th to endNight
4213323446%60%
1910
September1st to 15thNight
9%423313337%56%
1800
16th to endNight
7%212213335%64%
1955
October1st to 15thNight
13%312323447%52%
2118
16th to endNight
7%412423346%59%
2400
November1st to 15thNight
6%41332345%7%56%
2470
16th to endNight
441332445%7%58%
2633
December1st to 15thNight
5%6%35%42445%7%50%
2730
16th to endNight
5%6%24425%45%7%50%
2755

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
25%35%5%2445%9%49%
1432
16th to endDay
45%2432445%5%56%
1602
February1st to 15thDay
5%7%46%425%45%7%46%
1611
16th to endDay
5%7%45%5%2345%8%47%
1580
March1st to 15thDay
5%5%25%423449%52%
1800
16th to endDay
8%4245%345%5%8%47%
2222
April1st to 15thDay
8%5%35%4245%6%7%46%
2150
16th to endDay
13%6%25%5%3445%8%41%
2192
May1st to 15thDay
12%5%235%2445%6%44%
2408
16th to endDay
10%5%25%5%35%6%5%10%39%
2616
June1st to 15thDay
7%223325%5%7%9%49%
2520
16th to endDay
211232345%8%63%
2520
July1st to 15thDay
43133345%6%10%53%
2520
16th to endDay
42133245%6%10%55%
2656
August1st to 15thDay
42124246%7%10%52%
2371
16th to endDay
421332345%7%61%
2292
September1st to 15thDay
8%21231335%6%59%
2160
16th to endDay
6%32212347%63%
2004
October1st to 15thDay
12%423215%345%53%
1839
16th to endDay
5%22322346%7%59%
1812
November1st to 15thDay
5%41433435%9%55%
1718
16th to endDay
432332336%8%58%
1655
December1st to 15thDay
5%5%343246%6%8%50%
1560
16th to endDay
5%6%23425%5%49%48%
1568
January1st to 15thNight
46%344245%5%8%50%
2506
16th to endNight
45%25%5%245%47%53%
2631
February1st to 15thNight
5%7%245%245%5%8%46%
2240
16th to endNight
5%7%35%5%3345%6%49%
1894
March1st to 15thNight
5%6%2432346%8%51%
2160
16th to endNight
7%7%35%5%2346%7%47%
1997
April1st to 15thNight
9%6%245%2445%6%48%
1798
16th to endNight
15%5%244345%5%5%42%
1767
May1st to 15thNight
12%415%4345%47%45%
1541
16th to endNight
12%42443346%10%44%
1497
June1st to 15thNight
8%41433445%9%49%
1440
16th to endNight
21222447%8%61%
1440
July1st to 15thNight
5%2144345%6%8%52%
1440
16th to endNight
3212224448%61%
1512
August1st to 15thNight
2313435%48%10%52%
1584
16th to endNight
431432445%6%60%
1910
September1st to 15thNight
8%5%13323437%56%
1800
16th to endNight
7%212312435%64%
1955
October1st to 15thNight
13%313323448%51%
2118
16th to endNight
7%413323446%58%
2400
November1st to 15thNight
6%42332335%8%55%
2470
16th to endNight
4413323447%58%
2633
December1st to 15thNight
5%6%35%5%2445%7%49%
2730
16th to endNight
47%34425%45%7%50%
2755

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
30%5%18%32%11%1
1433
16th to endDay
28%5%18%31%14%2
1602
February1st to 15thDay
36%6%17%25%10%2
1612
16th to endDay
35%416%28%11%4
1580
March1st to 15thDay
29%415%29%17%4
1800
16th to endDay
33%7%14%28%13%2
2224
April1st to 15thDay
34%6%15%27%13%3
2150
16th to endDay
40%414%22%16%2
2192
May1st to 15thDay
38%6%13%26%13%1
2408
16th to endDay
38%6%17%24%10%2
2620
June1st to 15thDay
28%7%15%23%19%4
2520
16th to endDay
17%5%10%28%27%11%
2520
July1st to 15thDay
25%5%11%23%20%13%
2371
16th to endDay
21%5%11%25%24%12%
2489
August1st to 15thDay
24%6%13%26%17%11%
2355
16th to endDay
21%48%22%29%13%
2292
September1st to 15thDay
24%48%20%26%15%
2160
16th to endDay
20%38%30%30%6%
2004
October1st to 15thDay
31%5%10%24%21%5%
1839
16th to endDay
22%413%31%20%7%
1812
November1st to 15thDay
26%414%27%20%6%
1718
16th to endDay
24%314%32%23%2
1655
December1st to 15thDay
29%5%19%30%13%1
1560
16th to endDay
32%5%17%30%12%1
1568
January1st to 15thNight
30%5%17%28%14%2
2506
16th to endNight
29%5%15%31%14%2
2631
February1st to 15thNight
34%7%18%27%10%1
2250
16th to endNight
34%5%15%27%13%3
1894
March1st to 15thNight
29%5%13%28%17%4
2160
16th to endNight
35%5%15%26%15%2
1997
April1st to 15thNight
35%6%14%25%14%3
1798
16th to endNight
40%6%11%24%15%1
1767
May1st to 15thNight
37%5%15%25%14%1
1542
16th to endNight
35%7%18%22%12%2
1498
June1st to 15thNight
30%6%20%24%13%3
1440
16th to endNight
18%5%16%27%23%8%
1440
July1st to 15thNight
26%6%13%27%16%9%
1360
16th to endNight
19%5%13%28%21%12%
1416
August1st to 15thNight
23%7%18%25%15%8%
1576
16th to endNight
24%49%21%26%13%
1910
September1st to 15thNight
28%48%24%21%12%
1800
16th to endNight
22%36%33%25%8%
1955
October1st to 15thNight
31%414%21%22%5%
2118
16th to endNight
26%411%28%20%8%
2400
November1st to 15thNight
27%312%25%23%6%
2470
16th to endNight
25%412%32%19%4
2633
December1st to 15thNight
33%5%18%28%12%1
2730
16th to endNight
31%6%18%30%11%1
2755

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
7%7%28%25%16%13%
90
16th to endDay
7%47%28%13%3
96
February1st to 15thDay
8%13%51%25%1
90
16th to endDay
12%9%37%25%13%1
81
March1st to 15thDay
8%11%30%36%12%1
90
16th to endDay
12%13%37%26%8%
283
April1st to 15thDay
11%17%40%20%8%1
269
16th to endDay
18%17%26%25%10%1
302
May1st to 15thDay
17%6%28%26%17%3
468
16th to endDay
17%8%20%28%20%3
517
June1st to 15thDay
8%326%33%21%7%
495
16th to endDay
3427%36%25%2
495
July1st to 15thDay
6%218%33%31%6%
475
16th to endDay
6%218%35%31%5%
515
August1st to 15thDay
6%122%36%28%4
396
16th to endDay
4325%26%26%13%
332
September1st to 15thDay
8%5%21%30%25%8%
315
16th to endDay
11%325%23%25%10%
159
October1st to 15thDay
16%6%21%26%22%6%
135
16th to endDay
6%9%27%32%16%6%
144
November1st to 15thDay
5%421%41%17%9%
135
16th to endDay
12%9%29%40%8%
135
December1st to 15thDay
8%18%37%25%9%1
135
16th to endDay
8%337%37%11%1
108
January1st to 15thNight
6%10%38%31%10%1
900
16th to endNight
7%8%45%31%6%
903
February1st to 15thNight
8%5%44%33%6%
704
16th to endNight
11%6%40%34%6%
632
March1st to 15thNight
7%6%40%37%7%
720
16th to endNight
10%9%35%38%6%
650
April1st to 15thNight
10%10%41%33%5%
539
16th to endNight
18%7%29%34%9%
540
May1st to 15thNight
15%5%27%37%13%
540
16th to endNight
14%425%39%14%
563
June1st to 15thNight
11%331%39%13%
540
16th to endNight
2135%48%11%
540
July1st to 15thNight
6%19%51%20%
510
16th to endNight
4115%53%24%1
564
August1st to 15thNight
4116%56%21%
539
16th to endNight
5%118%50%23%
573
September1st to 15thNight
10%220%45%19%1
540
16th to endNight
8%225%44%18%
537
October1st to 15thNight
14%328%39%13%
678
16th to endNight
9%431%40%13%
864
November1st to 15thNight
8%6%34%38%11%
950
16th to endNight
6%6%36%43%6%
975
December1st to 15thNight
8%7%45%32%5%
975
16th to endNight
8%7%41%35%6%
984
Page generated at 2017-12-21 05:04:55. Version ac04

Copyright 2017 A. Danko


Torrington Clear Sky Chart |Charts Home