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 2017-09-22.

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
26%
14683
13%
46920
7%
14653
33%
14653
16%
33508

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
12%
720
6%
2506
2%
716
17%
716
6%
2051
January16th to endNight
18%
768
11%
2589
5%
768
25%
768
10%
1981
February1st to 15thNight
14%
702
9%
2287
3%
701
21%
701
10%
1773
February16th to endNight
17%
631
14%
1991
4%
631
29%
631
13%
1447
March1st to 15thNight
15%
720
13%
2046
5%
720
23%
720
13%
1535
March16th to endNight
27%
768
19%
2073
8%
768
37%
768
22%
1422
April1st to 15thNight
20%
718
15%
1796
4%
718
26%
718
19%
1347
April16th to endNight
29%
621
17%
1701
8%
621
35%
621
22%
1179
May1st to 15thNight
32%
375
17%
1455
13%
375
43%
375
16%
954
May16th to endNight
30%
375
14%
1497
9%
374
44%
374
19%
918
June1st to 15thNight
29%
360
9%
1440
6%
360
40%
360
16%
940
June16th to endNight
38%
360
10%
1440
12%
360
44%
360
19%
906
July1st to 15thNight
43%
340
15%
1360
18%
340
52%
340
26%
755
July16th to endNight
46%
376
15%
1418
13%
354
55%
354
27%
785
August1st to 15thNight
50%
504
14%
1575
10%
502
55%
502
28%
982
August16th to endNight
48%
668
21%
1814
10%
668
55%
668
37%
1110
September1st to 15thNight
41%
720
16%
1800
7%
720
44%
720
30%
1220
September16th to endNight
43%
685
22%
1883
13%
685
49%
685
31%
1204
October1st to 15thNight
27%
660
16%
1980
10%
660
37%
660
18%
1397
October16th to endNight
20%
704
10%
2159
4%
704
27%
704
12%
1685
November1st to 15thNight
25%
700
17%
2382
13%
700
33%
700
15%
1701
November16th to endNight
17%
720
9%
2520
6%
720
22%
720
9%
1970
December1st to 15thNight
13%
720
7%
2520
2%
720
18%
720
6%
2052
December16th to endNight
10%
768
7%
2688
3%
768
17%
768
7%
2194

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
18%10%47%6%34446%30%
47967
Night
16%11%47%6%34446%31%
47090
Cloud CoverDay
17%10%47%6%34446%30%
47977
Night
16%10%47%6%34446%31%
47095
TransparencyDay
54%5%10%18%9%1
47655
Night
53%5%11%19%9%
46920
SeeingDay
23%14%30%19%8%3
5415
Night
22%14%30%22%8%
14685

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
19%15%5%11%6%3443420%
1432
16th to endDay
13%15%6%11%9%5%4335%20%
1632
February1st to 15thDay
11%16%6%12%10%25%44420%
1575
16th to endDay
16%16%6%7%5%45%435%23%
1480
March1st to 15thDay
15%13%6%8%8%35%435%24%
1902
16th to endDay
13%10%47%5%23346%36%
2151
April1st to 15thDay
22%12%46%424235%31%
2152
16th to endDay
22%9%25%423335%38%
2268
May1st to 15thDay
21%9%36%424446%32%
2495
16th to endDay
16%6%26%5%35%46%7%33%
2618
June1st to 15thDay
23%7%35%5%3445%6%30%
2520
16th to endDay
18%6%36%5%35%5%5%8%32%
2520
July1st to 15thDay
14%6%35%5%36%5%5%8%36%
2520
16th to endDay
12%5%26%6%45%6%6%9%33%
2654
August1st to 15thDay
14%7%36%8%35%45%7%33%
2373
16th to endDay
14%5%25%6%35%5%6%9%35%
2375
September1st to 15thDay
19%7%24433446%38%
2160
16th to endDay
16%6%25%4245%45%41%
1887
October1st to 15thDay
23%10%35%433445%30%
1650
16th to endDay
29%12%46%6%2432421%
1713
November1st to 15thDay
15%11%46%5%34446%33%
1474
16th to endDay
21%16%6%8%5%35%34420%
1440
December1st to 15thDay
20%18%8%11%7%35%42414%
1440
16th to endDay
20%18%7%9%6%2433418%
1536
January1st to 15thNight
16%14%6%11%9%46%45%415%
2506
16th to endNight
11%16%6%8%9%34445%23%
2589
February1st to 15thNight
12%16%7%9%8%45%445%21%
2285
16th to endNight
14%13%5%7%7%34446%28%
1991
March1st to 15thNight
17%12%5%8%7%3433429%
2034
16th to endNight
13%9%46%6%2345%5%39%
2073
April1st to 15thNight
20%11%46%5%2343433%
1796
16th to endNight
17%9%35%433346%37%
1701
May1st to 15thNight
20%8%35%423337%36%
1455
16th to endNight
14%6%25%5%245%7%7%39%
1495
June1st to 15thNight
18%7%36%423448%36%
1440
16th to endNight
15%426%435%6%5%7%37%
1440
July1st to 15thNight
8%4146%35%5%47%48%
1440
16th to endNight
9%4244335%6%8%46%
1514
August1st to 15thNight
10%5%25%4345%7%8%43%
1585
16th to endNight
9%41443435%8%49%
1814
September1st to 15thNight
16%5%235%3445%7%42%
1800
16th to endNight
15%6%24323245%46%
1883
October1st to 15thNight
21%9%35%424346%34%
1980
16th to endNight
24%14%36%6%33446%23%
2159
November1st to 15thNight
16%11%45%6%35%445%31%
2382
16th to endNight
21%13%6%9%7%2433422%
2520
December1st to 15thNight
18%18%7%10%6%34335%17%
2520
16th to endNight
21%17%6%11%6%2433417%
2688

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
19%15%5%11%6%3434321%
1432
16th to endDay
13%15%6%11%9%5%5%345%20%
1632
February1st to 15thDay
12%15%6%13%10%3444420%
1575
16th to endDay
16%15%6%8%5%35%435%23%
1480
March1st to 15thDay
15%13%6%9%8%3444424%
1913
16th to endDay
13%10%47%5%33446%37%
2150
April1st to 15thDay
22%12%46%423335%32%
2152
16th to endDay
21%10%3442233438%
2268
May1st to 15thDay
20%9%36%424446%32%
2495
16th to endDay
16%7%36%6%35%45%7%33%
2618
June1st to 15thDay
23%7%36%5%2445%6%29%
2520
16th to endDay
17%6%36%5%35%5%5%8%31%
2520
July1st to 15thDay
13%5%35%6%45%5%6%8%35%
2520
16th to endDay
12%5%26%6%36%6%6%9%33%
2654
August1st to 15thDay
13%7%37%8%35%5%5%7%33%
2373
16th to endDay
13%5%25%6%35%46%8%35%
2375
September1st to 15thDay
18%7%35%434347%38%
2160
16th to endDay
16%6%25%5%345%36%40%
1887
October1st to 15thDay
23%11%26%5%24445%30%
1650
16th to endDay
29%12%46%6%2432421%
1713
November1st to 15thDay
16%10%46%6%24436%33%
1474
16th to endDay
21%15%6%8%5%35%44420%
1440
December1st to 15thDay
19%18%7%11%7%3443414%
1440
16th to endDay
20%18%7%10%6%2433417%
1536
January1st to 15thNight
16%14%6%12%9%46%45%415%
2506
16th to endNight
11%15%6%8%10%3445%5%23%
2589
February1st to 15thNight
12%16%7%8%8%45%45%5%21%
2278
16th to endNight
13%12%5%7%6%35%446%28%
1991
March1st to 15thNight
17%12%5%8%6%2434429%
2046
16th to endNight
12%9%46%6%23345%40%
2073
April1st to 15thNight
20%10%46%5%2333433%
1796
16th to endNight
17%8%35%5%3335%6%37%
1701
May1st to 15thNight
20%8%36%424336%36%
1455
16th to endNight
13%6%245%245%6%8%39%
1495
June1st to 15thNight
18%7%35%5%245%48%35%
1440
16th to endNight
14%5%25%436%5%5%8%37%
1440
July1st to 15thNight
8%425%5%35%5%47%48%
1440
16th to endNight
9%4245%2447%8%46%
1514
August1st to 15thNight
9%5%25%5%336%6%8%43%
1585
16th to endNight
8%5%2443336%7%49%
1814
September1st to 15thNight
15%5%2442445%6%42%
1800
16th to endNight
15%6%15%323345%47%
1883
October1st to 15thNight
21%9%35%424346%34%
1980
16th to endNight
23%13%47%6%34345%23%
2159
November1st to 15thNight
16%11%46%5%35%45%5%31%
2382
16th to endNight
21%14%5%9%7%3433422%
2520
December1st to 15thNight
18%18%7%10%6%34335%17%
2520
16th to endNight
21%16%6%11%6%2433417%
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
66%5%9%11%6%1
1433
16th to endDay
65%5%7%11%8%1
1632
February1st to 15thDay
66%39%13%5%
1577
16th to endDay
62%310%12%10%1
1480
March1st to 15thDay
62%310%15%6%1
1913
16th to endDay
47%38%20%14%4
2151
April1st to 15thDay
56%37%17%12%2
2152
16th to endDay
50%36%20%16%2
2268
May1st to 15thDay
52%49%17%13%2
2495
16th to endDay
49%5%11%20%11%2
2622
June1st to 15thDay
54%411%19%9%
2520
16th to endDay
49%6%10%20%12%1
2520
July1st to 15thDay
42%6%11%25%12%
2371
16th to endDay
45%8%13%23%8%
2487
August1st to 15thDay
48%6%14%19%9%
2359
16th to endDay
44%6%14%25%8%
2375
September1st to 15thDay
45%5%11%26%11%
2160
16th to endDay
44%5%11%28%10%
1887
October1st to 15thDay
55%410%17%10%
1650
16th to endDay
66%49%13%5%
1713
November1st to 15thDay
50%6%14%18%9%
1474
16th to endDay
65%49%12%5%1
1440
December1st to 15thDay
73%49%9%2
1440
16th to endDay
69%49%11%4
1536
January1st to 15thNight
70%410%9%4
2506
16th to endNight
61%5%9%15%7%
2589
February1st to 15thNight
63%413%13%5%
2287
16th to endNight
56%311%18%9%
1991
March1st to 15thNight
58%311%18%7%
2046
16th to endNight
46%410%21%16%2
2073
April1st to 15thNight
54%37%20%12%1
1796
16th to endNight
47%48%21%16%2
1701
May1st to 15thNight
49%37%19%16%3
1455
16th to endNight
40%7%13%22%14%2
1497
June1st to 15thNight
46%6%12%21%11%
1440
16th to endNight
42%7%12%23%13%
1440
July1st to 15thNight
33%6%12%29%17%1
1360
16th to endNight
33%6%16%29%13%
1418
August1st to 15thNight
36%7%18%25%11%
1575
16th to endNight
32%5%17%33%10%
1814
September1st to 15thNight
40%5%14%27%10%
1800
16th to endNight
38%412%35%8%
1883
October1st to 15thNight
51%410%20%12%
1980
16th to endNight
61%5%12%14%5%
2159
November1st to 15thNight
54%412%17%9%
2382
16th to endNight
64%411%14%3
2520
December1st to 15thNight
68%5%11%12%3
2520
16th to endNight
70%39%10%5%
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
33%21%28%8%8%
60
16th to endDay
35%18%31%12%2
80
February1st to 15thDay
30%25%38%32
90
16th to endDay
32%23%30%12%1
139
March1st to 15thDay
27%19%32%17%2
270
16th to endDay
24%19%31%14%7%1
288
April1st to 15thDay
27%24%27%14%6%
270
16th to endDay
28%20%24%12%11%2
270
May1st to 15thDay
33%10%25%17%7%5%
288
16th to endDay
25%14%33%15%8%1
331
June1st to 15thDay
27%13%31%18%9%
315
16th to endDay
18%13%33%22%9%2
315
July1st to 15thDay
13%8%32%32%8%3
305
16th to endDay
11%8%37%26%11%4
326
August1st to 15thDay
16%5%31%29%9%6%
313
16th to endDay
15%9%25%29%12%7%
332
September1st to 15thDay
20%7%25%20%14%10%
315
16th to endDay
18%7%27%25%12%8%
278
October1st to 15thDay
25%15%30%18%7%3
255
16th to endDay
34%16%29%14%4
263
November1st to 15thDay
19%15%33%20%9%1
128
16th to endDay
36%13%35%11%11
60
December1st to 15thDay
23%20%40%15%1
60
16th to endDay
35%40%18%4
64
January1st to 15thNight
24%22%33%15%4
720
16th to endNight
20%17%35%21%5%
768
February1st to 15thNight
20%19%39%16%3
704
16th to endNight
20%21%36%16%3
631
March1st to 15thNight
25%20%33%17%2
720
16th to endNight
18%19%30%22%8%1
768
April1st to 15thNight
27%19%29%19%4
718
16th to endNight
22%18%27%21%10%
621
May1st to 15thNight
26%9%26%28%8%
375
16th to endNight
18%9%36%25%9%
375
June1st to 15thNight
22%12%30%26%7%
360
16th to endNight
17%8%32%31%10%
360
July1st to 15thNight
10%6%33%35%13%1
340
16th to endNight
9%433%38%12%1
376
August1st to 15thNight
11%427%37%17%2
504
16th to endNight
11%5%29%33%17%2
668
September1st to 15thNight
20%6%28%25%16%3
720
16th to endNight
21%7%24%24%17%3
685
October1st to 15thNight
26%12%29%20%10%
660
16th to endNight
32%15%26%18%6%
704
November1st to 15thNight
24%16%28%20%9%1
700
16th to endNight
32%18%25%17%5%
720
December1st to 15thNight
27%23%29%15%3
720
16th to endNight
32%16%32%14%2
768
Page generated at 2017-09-23 06:43:38. Version ac04

Copyright 2017 A. Danko


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