Twillingate
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Twillingate 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
19%
23809
7%
74980
3%
23740
24%
23740
9%
61309

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
7%
849
3%
2839
1%
847
10%
847
3%
2565
January11th to 20thNight
6%
814
4%
2610
1%
814
10%
814
3%
2368
January21st to endNight
8%
880
7%
2772
1%
880
13%
880
5%
2395
February1st to 10thNight
8%
800
3%
2520
0%
800
11%
800
4%
2227
February11th to 20thNight
10%
765
5%
2247
0%
762
14%
762
7%
1895
February21st to endNight
17%
592
11%
1776
2%
592
23%
592
11%
1414
March1st to 10thNight
15%
720
10%
2160
3%
720
22%
720
9%
1743
March11th to 20thNight
22%
589
11%
2029
5%
589
28%
589
10%
1569
March21st to endNight
16%
594
9%
2105
4%
594
24%
594
8%
1688
April1st to 10thNight
13%
540
9%
1796
5%
540
20%
540
9%
1436
April11th to 20thNight
20%
534
11%
1598
6%
534
28%
534
14%
1225
April21st to endNight
24%
540
11%
1620
6%
540
29%
540
12%
1266
May1st to 10thNight
26%
540
7%
1535
3%
540
28%
540
11%
1246
May11th to 20thNight
25%
532
8%
1302
2%
532
28%
532
15%
1061
May21st to endNight
25%
583
6%
1357
2%
582
27%
582
15%
1116
June1st to 10thNight
25%
540
4%
1260
2%
540
26%
540
13%
1068
June11th to 20thNight
30%
540
3%
1260
2%
540
31%
540
17%
1020
June21st to endNight
32%
540
3%
1260
2%
540
34%
540
18%
1008
July1st to 10thNight
35%
526
5%
1226
2%
526
38%
526
22%
919
July11th to 20thNight
38%
522
6%
1218
3%
522
39%
522
24%
918
July21st to endNight
34%
590
7%
1469
3%
558
37%
558
17%
1132
August1st to 10thNight
37%
538
7%
1422
3%
534
39%
534
18%
1082
August11th to 20thNight
37%
532
10%
1590
7%
532
39%
532
19%
1152
August21st to endNight
41%
594
12%
1782
10%
594
45%
594
20%
1258
September1st to 10thNight
34%
540
12%
1781
10%
540
40%
540
19%
1230
September11th to 20thNight
28%
540
11%
1980
8%
540
35%
540
13%
1418
September21st to endNight
25%
540
12%
1980
6%
540
33%
540
14%
1409
October1st to 10thNight
23%
567
14%
2034
7%
567
30%
567
13%
1497
October11th to 20thNight
27%
774
10%
2304
5%
774
30%
774
13%
1779
October21st to endNight
18%
891
9%
2574
4%
891
22%
891
10%
2113
November1st to 10thNight
13%
830
8%
2436
2%
830
17%
830
7%
2036
November11th to 20thNight
14%
850
7%
2702
3%
850
18%
850
7%
2259
November21st to endNight
8%
850
6%
2850
1%
850
14%
850
5%
2413
December1st to 10thNight
12%
850
5%
2850
1%
850
16%
850
5%
2499
December11th to 20thNight
5%
850
1%
3531
0%
849
7%
849
1%
3330
December21st to endNight
8%
933
2%
5205
1%
907
10%
907
2%
4555

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
22%13%5%8%7%3445%6%24%
74601
Night
23%15%6%10%7%34445%19%
75157
TransparencyDay
63%412%15%6%
74291
Night
69%49%13%5%
75002
SeeingDay
29%10%26%23%10%2
16964
Night
31%11%27%22%8%1
23813

By Month

Percentage Cloud Cover NE (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
19%18%10%14%13%344349%
1326
11th to 20thDay
18%17%8%16%16%5%34339%
1411
21st to endDay
18%14%6%16%13%5%5%44311%
1584
February1st to 10thDay
18%13%5%13%17%5%5%5%46%11%
1440
11th to 20thDay
18%17%6%10%10%46%5%5%315%
1601
21st to endDay
14%13%5%11%9%6%9%5%45%20%
1480
March1st to 10thDay
20%12%5%10%7%5%5%5%4423%
1796
11th to 20thDay
19%13%6%9%8%35%45%6%22%
1931
21st to endDay
22%17%6%9%7%33445%21%
2250
April1st to 10thDay
20%15%5%8%6%4445%6%22%
2163
11th to 20thDay
22%13%6%6%43435%6%27%
2311
21st to endDay
20%16%6%9%5%34345%25%
2340
May1st to 10thDay
24%16%5%8%6%44445%22%
2421
11th to 20thDay
24%12%47%5%3445%5%27%
2591
21st to endDay
24%13%47%5%3445%6%25%
2918
June1st to 10thDay
29%13%46%5%34445%21%
2700
11th to 20thDay
27%10%47%5%3445%6%25%
2700
21st to endDay
22%10%47%5%35%5%5%6%27%
2700
July1st to 10thDay
21%9%36%5%45%5%5%7%32%
2700
11th to 20thDay
18%7%35%6%35%45%7%36%
2700
21st to endDay
19%10%37%6%45%5%6%7%28%
2761
August1st to 10thDay
21%11%46%5%345%6%7%30%
2506
11th to 20thDay
19%9%5%6%4335%47%35%
2310
21st to endDay
20%8%35%5%345%7%8%33%
2574
September1st to 10thDay
21%8%36%5%24447%36%
2177
11th to 20thDay
27%9%36%5%2445%6%29%
1980
21st to endDay
20%9%36%5%345%6%7%32%
1980
October1st to 10thDay
23%12%36%5%34346%32%
1926
11th to 20thDay
23%16%38%6%24447%23%
1652
21st to endDay
28%17%37%5%245%46%19%
1782
November1st to 10thDay
25%19%5%7%5%34445%19%
1642
11th to 20thDay
21%18%8%8%7%34345%19%
1478
21st to endDay
23%17%9%11%6%2434417%
1330
December1st to 10thDay
23%17%9%14%5%34445%12%
1330
11th to 20thDay
25%17%9%15%8%233349%
1668
21st to endDay
25%17%7%21%10%343326%
2442
January1st to 10thNight
19%17%10%15%14%45%3337%
2839
11th to 20thNight
17%17%7%18%14%6%43348%
2610
21st to endNight
18%16%7%16%12%5%434411%
2772
February1st to 10thNight
18%13%6%16%17%5%5%33310%
2520
11th to 20thNight
20%16%7%9%10%45%445%15%
2243
21st to endNight
15%11%7%11%10%47%45%6%21%
1776
March1st to 10thNight
18%18%5%10%8%44345%21%
2151
11th to 20thNight
17%14%6%10%7%6%5%5%5%6%21%
2028
21st to endNight
23%17%5%10%7%34445%19%
2105
April1st to 10thNight
23%17%6%9%6%34345%20%
1796
11th to 20thNight
24%15%7%8%423345%26%
1598
21st to endNight
25%16%6%5%5%34345%24%
1620
May1st to 10thNight
29%16%46%6%3334421%
1535
11th to 20thNight
30%13%5%6%5%3433424%
1301
21st to endNight
29%14%5%5%434446%23%
1356
June1st to 10thNight
32%12%5%7%5%25%446%18%
1260
11th to 20thNight
29%11%47%5%345%45%23%
1260
21st to endNight
26%13%37%4245%5%6%26%
1260
July1st to 10thNight
24%10%36%5%3445%7%29%
1260
11th to 20thNight
18%8%36%8%35%5%5%7%32%
1260
21st to endNight
23%10%47%7%34446%28%
1555
August1st to 10thNight
21%9%37%8%346%6%6%26%
1433
11th to 20thNight
22%10%36%5%25%446%32%
1590
21st to endNight
23%8%25%5%3445%8%32%
1782
September1st to 10thNight
23%8%36%42445%7%34%
1781
11th to 20thNight
25%11%36%434346%30%
1980
21st to endNight
22%11%47%5%2445%6%31%
1980
October1st to 10thNight
25%11%27%5%34446%27%
2034
11th to 20thNight
25%14%46%5%35%45%6%23%
2304
21st to endNight
31%19%36%422345%21%
2574
November1st to 10thNight
25%18%48%6%35%445%17%
2436
11th to 20thNight
24%19%7%8%5%34446%15%
2702
21st to endNight
23%18%10%11%6%34335%14%
2850
December1st to 10thNight
21%19%9%14%7%4443411%
2850
11th to 20thNight
29%20%9%17%10%222225%
3531
21st to endNight
24%16%9%19%8%3223410%
5225

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
82%47%5%2
1327
11th to 20thDay
83%46%5%2
1411
21st to endDay
77%45%9%4
1584
February1st to 10thDay
75%48%6%5%1
1440
11th to 20thDay
74%39%10%5%
1608
21st to endDay
67%48%13%8%1
1480
March1st to 10thDay
65%48%13%9%1
1800
11th to 20thDay
64%5%9%15%7%1
1931
21st to endDay
68%48%13%8%1
2250
April1st to 10thDay
64%39%16%7%1
2163
11th to 20thDay
60%210%18%9%1
2311
21st to endDay
65%37%16%9%
2340
May1st to 10thDay
66%39%15%6%1
2421
11th to 20thDay
60%311%17%8%1
2595
21st to endDay
59%413%17%6%
2918
June1st to 10thDay
66%410%16%4
2700
11th to 20thDay
60%412%19%5%1
2700
21st to endDay
57%5%13%17%7%1
2700
July1st to 10thDay
51%417%22%6%
2625
11th to 20thDay
49%418%23%6%
2618
21st to endDay
54%6%17%19%5%
2607
August1st to 10thDay
54%5%17%21%3
2492
11th to 20thDay
52%319%20%6%
2310
21st to endDay
49%5%20%21%5%
2574
September1st to 10thDay
49%5%13%24%8%1
2177
11th to 20thDay
57%414%19%7%
1980
21st to endDay
51%420%19%7%
1980
October1st to 10thDay
56%410%20%8%
1926
11th to 20thDay
63%413%15%4
1652
21st to endDay
67%39%14%6%1
1782
November1st to 10thDay
70%5%11%10%4
1642
11th to 20thDay
68%411%10%5%1
1478
21st to endDay
72%5%9%9%5%
1330
December1st to 10thDay
77%49%8%3
1330
11th to 20thDay
82%29%42
1667
21st to endDay
87%25%41
2442
January1st to 10thNight
83%35%5%31
2839
11th to 20thNight
82%45%6%2
2610
21st to endNight
75%5%6%9%4
2772
February1st to 10thNight
79%46%7%4
2520
11th to 20thNight
73%39%11%4
2247
21st to endNight
64%5%8%15%7%1
1776
March1st to 10thNight
67%47%13%8%1
2160
11th to 20thNight
64%49%15%7%1
2029
21st to endNight
69%36%13%9%1
2105
April1st to 10thNight
68%36%14%8%
1796
11th to 20thNight
63%210%18%8%1
1598
21st to endNight
64%48%16%8%1
1620
May1st to 10thNight
68%38%14%6%1
1535
11th to 20thNight
65%37%17%6%1
1302
21st to endNight
64%5%11%13%7%1
1357
June1st to 10thNight
68%5%10%12%5%
1260
11th to 20thNight
63%412%17%5%
1260
21st to endNight
60%5%11%17%6%1
1260
July1st to 10thNight
54%416%21%5%
1226
11th to 20thNight
52%5%14%21%8%
1218
21st to endNight
59%5%12%21%4
1469
August1st to 10thNight
56%6%15%18%5%
1422
11th to 20thNight
53%5%15%20%6%
1590
21st to endNight
52%417%20%7%
1782
September1st to 10thNight
51%413%23%9%1
1781
11th to 20thNight
57%412%18%8%
1980
21st to endNight
55%5%14%19%7%1
1980
October1st to 10thNight
59%411%17%8%1
2034
11th to 20thNight
63%312%17%4
2304
21st to endNight
69%39%12%6%1
2574
November1st to 10thNight
70%49%11%5%
2436
11th to 20thNight
71%5%9%12%2
2702
21st to endNight
73%5%8%8%5%
2850
December1st to 10thNight
78%47%9%2
2850
11th to 20thNight
90%2431
3533
21st to endNight
82%36%7%2
5225

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
28%15%34%19%5%
370
11th to 20thDay
26%17%35%19%3
349
21st to endDay
29%20%31%18%2
374
February1st to 10thDay
25%22%34%16%3
340
11th to 20thDay
23%22%36%16%21
336
21st to endDay
20%16%39%16%5%3
280
March1st to 10thDay
25%11%38%19%6%1
340
11th to 20thDay
26%16%24%21%11%2
340
21st to endDay
33%12%27%18%7%2
406
April1st to 10thDay
28%12%32%20%6%1
423
11th to 20thDay
32%8%25%25%7%3
589
21st to endDay
31%7%29%24%8%1
600
May1st to 10thDay
35%7%23%21%11%3
603
11th to 20thDay
28%426%25%13%3
624
21st to endDay
34%6%23%26%10%1
680
June1st to 10thDay
38%6%20%22%10%3
630
11th to 20thDay
32%5%19%27%14%3
630
21st to endDay
26%222%29%16%4
630
July1st to 10thDay
27%423%30%12%4
620
11th to 20thDay
24%321%28%22%2
618
21st to endDay
25%420%34%16%1
685
August1st to 10thDay
27%5%18%31%15%4
625
11th to 20thDay
24%322%28%20%3
617
21st to endDay
27%421%25%18%5%
693
September1st to 10thDay
28%8%24%27%11%3
474
11th to 20thDay
36%9%22%25%7%1
360
21st to endDay
25%9%37%21%6%2
360
October1st to 10thDay
26%13%33%19%7%1
360
11th to 20thDay
38%9%23%16%12%2
360
21st to endDay
34%14%27%17%6%2
396
November1st to 10thDay
40%13%30%14%3
365
11th to 20thDay
34%19%24%17%6%1
370
21st to endDay
34%17%34%14%2
370
December1st to 10thDay
29%14%32%18%6%
370
11th to 20thDay
32%24%26%16%2
370
21st to endDay
28%19%31%17%5%1
407
January1st to 10thNight
28%18%30%18%5%1
850
11th to 20thNight
27%17%37%14%5%
814
21st to endNight
26%18%36%17%3
880
February1st to 10thNight
27%21%32%18%3
800
11th to 20thNight
29%17%34%15%31
766
21st to endNight
23%11%37%19%7%2
592
March1st to 10thNight
27%15%32%20%5%1
720
11th to 20thNight
25%10%30%25%10%1
589
21st to endNight
34%12%26%22%6%1
594
April1st to 10thNight
32%11%31%19%6%1
540
11th to 20thNight
32%7%28%21%10%1
534
21st to endNight
35%425%29%6%1
540
May1st to 10thNight
37%5%19%27%11%2
540
11th to 20thNight
39%5%18%23%12%2
532
21st to endNight
36%5%24%26%8%1
583
June1st to 10thNight
38%6%17%29%10%1
540
11th to 20thNight
36%317%27%14%2
540
21st to endNight
32%420%27%14%1
540
July1st to 10thNight
28%422%33%12%2
526
11th to 20thNight
25%324%36%12%1
522
21st to endNight
27%421%34%14%1
590
August1st to 10thNight
27%318%35%16%1
538
11th to 20thNight
25%321%32%17%1
532
21st to endNight
28%419%31%17%2
594
September1st to 10thNight
27%5%25%31%11%1
540
11th to 20thNight
32%9%24%29%6%
540
21st to endNight
32%6%32%24%6%1
540
October1st to 10thNight
35%8%29%22%7%1
567
11th to 20thNight
35%9%22%23%10%1
774
21st to endNight
40%13%20%20%6%1
891
November1st to 10thNight
35%16%27%18%4
830
11th to 20thNight
35%12%28%18%6%1
850
21st to endNight
34%17%31%15%3
850
December1st to 10thNight
32%14%29%19%5%1
850
11th to 20thNight
36%17%30%14%4
850
21st to endNight
26%19%30%18%6%1
935
Page generated at 2024-01-10 21:35:26. Version ac07

Copyright 2024 Attilla Danko


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