Quadeville Road
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Quadeville Road clear sky chart from 2005-11-05 to 2019-06-19.

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
25%
16882
13%
53991
7%
16852
33%
16852
16%
38552

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
13%
840
7%
2926
2%
836
19%
836
7%
2359
January16th to endNight
17%
896
10%
3021
5%
896
24%
896
10%
2324
February1st to 15thNight
12%
822
10%
2677
2%
821
22%
821
10%
2068
February16th to endNight
16%
735
13%
2319
4%
735
27%
735
13%
1697
March1st to 15thNight
15%
840
13%
2388
5%
840
23%
840
13%
1802
March16th to endNight
27%
896
20%
2419
8%
896
37%
896
23%
1646
April1st to 15thNight
18%
838
16%
2096
4%
838
24%
838
18%
1575
April16th to endNight
30%
716
16%
1962
7%
716
35%
716
21%
1370
May1st to 15thNight
31%
438
19%
1698
14%
438
43%
438
16%
1107
May16th to endNight
30%
439
14%
1753
9%
438
45%
438
20%
1049
June1st to 15thNight
30%
420
11%
1680
9%
420
40%
420
17%
1085
June16th to endNight
37%
398
10%
1592
12%
398
43%
398
19%
993
July1st to 15thNight
44%
370
17%
1480
20%
370
54%
370
28%
801
July16th to endNight
45%
408
15%
1546
14%
386
54%
386
26%
857
August1st to 15thNight
50%
537
14%
1678
10%
535
55%
535
27%
1060
August16th to endNight
48%
724
20%
1966
9%
724
55%
724
36%
1217
September1st to 15thNight
42%
780
18%
1950
8%
780
45%
780
31%
1311
September16th to endNight
43%
777
21%
2143
13%
777
48%
777
30%
1374
October1st to 15thNight
27%
780
15%
2340
9%
780
36%
780
18%
1652
October16th to endNight
19%
832
11%
2551
5%
832
28%
832
12%
1968
November1st to 15thNight
24%
820
16%
2790
11%
820
32%
820
14%
2021
November16th to endNight
17%
840
9%
2940
6%
840
21%
840
9%
2302
December1st to 15thNight
14%
840
8%
2940
3%
840
20%
840
7%
2380
December16th to endNight
11%
896
8%
3136
3%
896
18%
896
7%
2534

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
17%10%47%6%34446%30%
54737
Night
16%11%47%6%34446%31%
54161
Cloud CoverDay
17%10%47%6%34446%30%
54747
Night
15%10%47%6%34446%31%
54166
TransparencyDay
54%5%10%18%10%1
54425
Night
53%5%11%19%9%
53991
SeeingDay
24%15%30%18%7%2
7536
Night
22%14%31%22%8%
16884

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 15thDay
18%14%5%12%7%3443420%
1672
16th to endDay
13%14%6%11%9%5%5%435%20%
1904
February1st to 15thDay
12%16%6%12%10%25%445%20%
1845
16th to endDay
16%16%6%7%6%45%445%22%
1724
March1st to 15thDay
15%15%6%8%8%35%43425%
2220
16th to endDay
13%10%47%6%23346%37%
2509
April1st to 15thDay
22%13%46%5%24235%29%
2512
16th to endDay
22%10%25%423335%37%
2614
May1st to 15thDay
21%9%36%423346%33%
2912
16th to endDay
16%7%26%6%35%46%7%34%
3066
June1st to 15thDay
23%7%35%5%34446%31%
2940
16th to endDay
18%6%35%5%35%5%5%8%33%
2776
July1st to 15thDay
13%5%35%5%35%5%5%8%38%
2730
16th to endDay
12%6%26%6%45%6%6%9%33%
2878
August1st to 15thDay
14%7%36%8%35%45%7%32%
2523
16th to endDay
14%5%25%6%45%46%8%35%
2574
September1st to 15thDay
18%7%2443345%7%37%
2340
16th to endDay
16%6%25%5%245%45%41%
2145
October1st to 15thDay
22%10%35%5%33445%29%
1950
16th to endDay
27%13%47%6%2433422%
2025
November1st to 15thDay
17%12%47%5%34335%31%
1726
16th to endDay
21%16%6%8%6%35%34419%
1680
December1st to 15thDay
19%18%8%11%7%45%43414%
1680
16th to endDay
18%17%7%11%6%2433418%
1792
January1st to 15thNight
16%14%6%12%8%35%445%16%
2926
16th to endNight
12%15%6%9%9%34445%22%
3021
February1st to 15thNight
12%16%7%9%8%45%445%21%
2675
16th to endNight
13%13%5%8%7%34446%28%
2319
March1st to 15thNight
16%13%5%8%6%3433428%
2376
16th to endNight
12%8%46%6%23446%40%
2419
April1st to 15thNight
20%11%46%5%33435%32%
2096
16th to endNight
19%8%3443335%6%36%
1962
May1st to 15thNight
20%8%25%423437%36%
1698
16th to endNight
13%5%25%5%245%6%8%41%
1751
June1st to 15thNight
18%6%36%423447%37%
1680
16th to endNight
14%426%425%6%5%7%38%
1592
July1st to 15thNight
7%3145%35%447%50%
1560
16th to endNight
9%4244335%5%8%45%
1642
August1st to 15thNight
10%5%25%5%345%6%8%42%
1688
16th to endNight
9%5%2443435%8%48%
1966
September1st to 15thNight
15%5%235%245%47%43%
1950
16th to endNight
15%6%24423345%46%
2143
October1st to 15thNight
21%8%35%5%24346%34%
2340
16th to endNight
22%13%36%6%33445%25%
2551
November1st to 15thNight
17%12%46%6%34445%29%
2790
16th to endNight
21%14%6%9%6%24345%21%
2940
December1st to 15thNight
17%18%8%10%7%34345%17%
2940
16th to endNight
19%16%6%11%7%3433418%
3136

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
18%14%5%12%7%3444320%
1672
16th to endDay
13%14%6%11%8%5%5%445%20%
1904
February1st to 15thDay
12%16%6%12%9%35%445%20%
1845
16th to endDay
16%15%6%8%5%45%445%23%
1724
March1st to 15thDay
15%15%6%9%8%3443425%
2231
16th to endDay
12%10%47%6%33445%37%
2508
April1st to 15thDay
21%12%47%5%23335%29%
2512
16th to endDay
22%10%25%42333437%
2614
May1st to 15thDay
20%9%36%5%24446%33%
2912
16th to endDay
15%7%36%6%35%45%7%34%
3066
June1st to 15thDay
23%7%36%5%2445%6%30%
2940
16th to endDay
17%6%26%5%35%5%5%7%33%
2776
July1st to 15thDay
12%5%35%5%45%5%6%7%38%
2730
16th to endDay
12%5%26%6%46%6%6%9%33%
2878
August1st to 15thDay
13%7%37%8%35%5%5%7%32%
2523
16th to endDay
14%6%25%6%35%5%6%8%35%
2574
September1st to 15thDay
18%7%25%42435%7%37%
2340
16th to endDay
15%6%25%5%345%36%41%
2145
October1st to 15thDay
22%11%36%5%245%45%29%
1950
16th to endDay
26%12%47%6%35%32422%
2025
November1st to 15thDay
17%11%47%6%24435%31%
1726
16th to endDay
21%15%6%8%6%35%44419%
1680
December1st to 15thDay
18%18%7%11%8%45%43414%
1680
16th to endDay
18%17%7%10%6%3434418%
1792
January1st to 15thNight
16%14%5%12%8%36%45%417%
2926
16th to endNight
12%15%6%9%10%3445%5%22%
3021
February1st to 15thNight
12%16%7%8%8%45%445%22%
2668
16th to endNight
13%12%6%8%7%45%446%28%
2319
March1st to 15thNight
16%13%5%8%6%2434428%
2388
16th to endNight
12%8%47%5%23445%40%
2419
April1st to 15thNight
20%10%46%5%2333433%
2096
16th to endNight
19%8%345%33346%36%
1962
May1st to 15thNight
19%8%36%424437%36%
1698
16th to endNight
13%6%245%2446%8%41%
1751
June1st to 15thNight
17%6%35%5%245%48%36%
1680
16th to endNight
14%5%25%435%5%5%8%39%
1592
July1st to 15thNight
7%4245%35%5%47%50%
1560
16th to endNight
9%4245%3447%8%45%
1642
August1st to 15thNight
9%6%25%5%346%6%8%42%
1688
16th to endNight
8%5%2443436%7%48%
1966
September1st to 15thNight
14%5%244245%5%7%43%
1950
16th to endNight
15%6%14324345%46%
2143
October1st to 15thNight
20%8%35%5%24346%34%
2340
16th to endNight
22%13%47%6%34345%25%
2551
November1st to 15thNight
17%11%47%5%35%345%30%
2790
16th to endNight
20%15%5%9%6%34345%21%
2940
December1st to 15thNight
17%17%7%11%7%34345%17%
2940
16th to endNight
20%15%6%11%7%3433418%
3136

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
66%48%11%7%1
1673
16th to endDay
64%6%8%11%7%1
1904
February1st to 15thDay
65%49%14%5%
1847
16th to endDay
62%39%12%10%1
1724
March1st to 15thDay
63%310%15%6%1
2231
16th to endDay
48%38%20%14%4
2509
April1st to 15thDay
58%37%16%12%2
2512
16th to endDay
51%36%19%16%2
2614
May1st to 15thDay
52%48%18%13%2
2912
16th to endDay
48%5%12%20%11%2
3070
June1st to 15thDay
53%410%18%11%1
2940
16th to endDay
48%6%10%20%12%1
2776
July1st to 15thDay
40%6%10%27%13%1
2581
16th to endDay
46%7%12%23%9%
2711
August1st to 15thDay
49%7%14%19%9%
2509
16th to endDay
45%6%14%24%8%
2574
September1st to 15thDay
44%5%11%25%11%
2340
16th to endDay
44%5%11%28%10%
2145
October1st to 15thDay
56%5%10%17%9%
1950
16th to endDay
65%410%14%4
2025
November1st to 15thDay
53%6%13%16%8%
1726
16th to endDay
66%5%9%11%5%1
1680
December1st to 15thDay
72%5%9%9%3
1680
16th to endDay
68%48%12%5%
1792
January1st to 15thNight
68%410%11%5%
2926
16th to endNight
61%5%8%15%8%
3021
February1st to 15thNight
63%412%14%5%
2677
16th to endNight
56%410%18%9%
2319
March1st to 15thNight
58%310%18%7%
2388
16th to endNight
45%310%21%16%2
2419
April1st to 15thNight
54%37%20%12%1
2096
16th to endNight
48%48%19%17%2
1962
May1st to 15thNight
48%47%20%16%2
1698
16th to endNight
38%7%13%22%15%2
1753
June1st to 15thNight
46%5%12%21%12%1
1680
16th to endNight
41%8%11%24%13%
1592
July1st to 15thNight
31%6%11%28%19%1
1480
16th to endNight
34%6%16%30%13%
1546
August1st to 15thNight
37%8%17%24%11%
1678
16th to endNight
33%5%16%32%11%
1966
September1st to 15thNight
39%6%14%27%11%
1950
16th to endNight
38%412%35%8%
2143
October1st to 15thNight
50%411%20%12%
2340
16th to endNight
60%5%12%15%5%
2551
November1st to 15thNight
55%412%17%8%
2790
16th to endNight
64%411%14%3
2940
December1st to 15thNight
67%5%10%12%3
2940
16th to endNight
68%49%10%5%
3136

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
28%19%35%10%6%
120
16th to endDay
28%23%36%10%1
160
February1st to 15thDay
32%27%35%21
180
16th to endDay
33%24%30%10%
227
March1st to 15thDay
28%18%32%17%2
390
16th to endDay
24%20%32%15%6%1
416
April1st to 15thDay
30%23%27%12%6%
390
16th to endDay
30%19%25%12%9%2
379
May1st to 15thDay
32%15%26%15%6%3
408
16th to endDay
23%17%35%15%6%1
459
June1st to 15thDay
28%13%31%18%7%
435
16th to endDay
18%14%33%22%9%1
388
July1st to 15thDay
12%7%32%33%10%3
365
16th to endDay
14%7%37%25%11%3
390
August1st to 15thDay
17%5%33%28%9%6%
358
16th to endDay
17%8%25%29%12%7%
396
September1st to 15thDay
19%8%26%20%14%10%
375
16th to endDay
18%10%28%23%12%7%
374
October1st to 15thDay
25%17%32%16%6%2
375
16th to endDay
33%19%28%14%3
383
November1st to 15thDay
30%17%27%16%7%1
200
16th to endDay
35%20%34%7%
120
December1st to 15thDay
25%18%37%15%2
120
16th to endDay
29%31%27%9%2
128
January1st to 15thNight
24%21%33%15%4
840
16th to endNight
20%19%35%19%4
896
February1st to 15thNight
21%20%38%15%3
824
16th to endNight
19%22%37%17%3
735
March1st to 15thNight
26%19%33%16%3
840
16th to endNight
18%18%31%22%8%
896
April1st to 15thNight
28%18%30%18%4
838
16th to endNight
25%16%25%21%10%
716
May1st to 15thNight
25%9%28%26%9%
438
16th to endNight
16%10%36%26%8%
439
June1st to 15thNight
21%11%30%27%7%
420
16th to endNight
16%8%32%31%11%
398
July1st to 15thNight
9%6%33%35%13%1
370
16th to endNight
9%433%38%12%1
408
August1st to 15thNight
11%427%37%18%2
537
16th to endNight
11%5%29%33%16%2
724
September1st to 15thNight
19%6%28%25%17%3
780
16th to endNight
20%8%25%24%17%3
777
October1st to 15thNight
25%12%30%20%9%1
780
16th to endNight
31%15%28%18%5%
832
November1st to 15thNight
26%16%28%19%8%1
820
16th to endNight
32%17%26%17%4
840
December1st to 15thNight
26%22%30%16%3
840
16th to endNight
30%16%32%16%2
896
Page generated at 2019-06-20 08:02:29. Version ac04

Copyright 2019 A. Danko


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