Deep River
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Deep River clear sky chart from 2005-11-05 to 2017-12-04.

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
32%
14920
12%
47674
8%
14891
37%
14891
16%
34513

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
17%
720
5%
2506
3%
716
20%
716
5%
2081
January16th to endNight
26%
768
11%
2602
6%
768
33%
768
11%
1981
February1st to 15thNight
21%
702
9%
2287
5%
701
26%
701
10%
1789
February16th to endNight
22%
631
11%
2003
6%
631
29%
631
12%
1538
March1st to 15thNight
23%
720
12%
2045
7%
720
28%
720
14%
1577
March16th to endNight
32%
768
20%
2073
10%
768
39%
768
22%
1424
April1st to 15thNight
27%
718
16%
1796
6%
718
32%
718
20%
1335
April16th to endNight
33%
603
17%
1683
9%
603
39%
603
23%
1177
May1st to 15thNight
33%
366
17%
1446
16%
366
41%
366
17%
957
May16th to endNight
38%
374
13%
1497
12%
374
48%
374
18%
940
June1st to 15thNight
36%
360
8%
1440
7%
360
43%
360
17%
944
June16th to endNight
46%
360
10%
1302
11%
360
51%
360
21%
833
July1st to 15thNight
50%
340
14%
1312
18%
340
55%
340
28%
732
July16th to endNight
57%
376
13%
1418
15%
354
61%
354
25%
811
August1st to 15thNight
54%
491
14%
1562
12%
489
58%
489
27%
984
August16th to endNight
55%
654
19%
1800
11%
654
59%
654
34%
1120
September1st to 15thNight
45%
720
16%
1800
7%
720
47%
720
29%
1236
September16th to endNight
49%
717
20%
1981
13%
717
53%
717
30%
1280
October1st to 15thNight
32%
720
16%
2160
11%
720
39%
720
20%
1518
October16th to endNight
26%
768
11%
2361
7%
768
33%
768
13%
1840
November1st to 15thNight
29%
760
14%
2608
11%
760
35%
760
14%
1909
November16th to endNight
21%
780
8%
2730
5%
780
25%
780
9%
2172
December1st to 15thNight
17%
736
6%
2574
3%
736
21%
736
7%
2120
December16th to endNight
16%
768
7%
2688
4%
768
20%
768
7%
2215

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%29%
48815
Night
18%11%47%6%34445%30%
47844
TransparencyDay
54%411%19%9%1
48503
Night
55%411%19%9%
47674
SeeingDay
24%9%27%22%12%4
5780
Night
24%9%25%27%11%
14923

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
21%16%7%9%7%3332320%
1432
16th to endDay
14%14%7%9%7%35%35%5%21%
1620
February1st to 15thDay
10%15%7%11%10%46%445%18%
1575
16th to endDay
17%15%6%8%6%2433424%
1469
March1st to 15thDay
17%14%5%8%5%3335%5%26%
1903
16th to endDay
13%8%47%5%34446%38%
2150
April1st to 15thDay
24%11%46%422235%30%
2152
16th to endDay
22%8%25%5%23235%36%
2288
May1st to 15thDay
21%10%36%5%24445%30%
2504
16th to endDay
18%6%45%6%3445%6%34%
2618
June1st to 15thDay
21%7%46%6%35%5%5%6%27%
2520
16th to endDay
17%5%25%6%36%5%6%7%33%
2651
July1st to 15thDay
16%436%6%45%5%6%7%34%
2562
16th to endDay
13%5%35%5%46%5%6%9%33%
2654
August1st to 15thDay
13%7%37%6%45%45%7%32%
2386
16th to endDay
13%6%26%5%36%5%5%9%34%
2390
September1st to 15thDay
17%6%25%5%33446%37%
2160
16th to endDay
19%6%24414335%42%
1977
October1st to 15thDay
22%8%37%5%24345%31%
1800
16th to endDay
30%13%46%5%33345%20%
1863
November1st to 15thDay
19%12%48%5%3445%5%28%
1577
16th to endDay
28%17%6%7%43433317%
1560
December1st to 15thDay
21%18%6%9%7%35%43413%
1468
16th to endDay
22%20%6%8%6%23345%16%
1536
January1st to 15thNight
20%17%7%10%7%35%43314%
2506
16th to endNight
13%17%5%9%7%34445%22%
2602
February1st to 15thNight
13%12%6%12%9%45%44421%
2285
16th to endNight
17%15%5%10%6%3433424%
2003
March1st to 15thNight
18%13%47%9%34335%26%
2033
16th to endNight
13%10%5%6%41334440%
2073
April1st to 15thNight
22%10%35%434345%32%
1796
16th to endNight
20%8%24424446%35%
1683
May1st to 15thNight
22%7%27%5%12346%35%
1446
16th to endNight
15%6%35%5%35%35%7%37%
1495
June1st to 15thNight
18%7%35%5%35%45%6%34%
1440
16th to endNight
14%5%345%35%6%6%9%35%
1302
July1st to 15thNight
11%42433445%7%46%
1392
16th to endNight
11%324335%46%9%42%
1514
August1st to 15thNight
13%5%146%35%5%6%7%41%
1572
16th to endNight
10%4245%3445%9%45%
1800
September1st to 15thNight
16%6%35%423347%41%
1800
16th to endNight
15%5%25%423346%45%
1981
October1st to 15thNight
22%8%25%42334436%
2160
16th to endNight
27%11%36%5%3435%423%
2361
November1st to 15thNight
20%11%37%6%35%345%29%
2608
16th to endNight
26%15%5%8%6%2333420%
2730
December1st to 15thNight
23%18%5%9%6%3433316%
2574
16th to endNight
24%17%6%9%6%2433416%
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
68%48%12%6%
1433
16th to endDay
63%310%14%6%
1620
February1st to 15thDay
69%38%13%5%
1577
16th to endDay
63%29%14%9%
1469
March1st to 15thDay
59%311%17%8%1
1914
16th to endDay
46%49%20%15%4
2150
April1st to 15thDay
56%27%18%11%2
2152
16th to endDay
50%26%20%15%2
2288
May1st to 15thDay
54%39%16%14%2
2504
16th to endDay
49%5%9%21%11%2
2622
June1st to 15thDay
55%411%18%9%
2520
16th to endDay
47%6%11%21%11%1
2651
July1st to 15thDay
42%5%12%26%11%1
2413
16th to endDay
45%5%14%24%9%
2487
August1st to 15thDay
47%5%16%19%10%
2372
16th to endDay
43%6%15%25%8%
2390
September1st to 15thDay
44%6%13%24%10%
2160
16th to endDay
45%413%30%6%
1977
October1st to 15thDay
53%412%18%9%
1800
16th to endDay
65%411%13%3
1863
November1st to 15thDay
56%5%13%17%7%
1577
16th to endDay
71%39%10%4
1560
December1st to 15thDay
72%49%11%2
1468
16th to endDay
71%39%12%3
1536
January1st to 15thNight
73%39%9%3
2506
16th to endNight
62%48%16%7%
2602
February1st to 15thNight
64%311%15%4
2287
16th to endNight
63%29%17%6%
2003
March1st to 15thNight
61%39%17%7%
2045
16th to endNight
46%48%20%16%3
2073
April1st to 15thNight
53%36%20%13%2
1796
16th to endNight
49%38%20%15%3
1683
May1st to 15thNight
50%36%19%16%2
1446
16th to endNight
45%5%11%22%13%2
1497
June1st to 15thNight
48%5%12%22%10%
1440
16th to endNight
41%7%13%23%12%
1302
July1st to 15thNight
32%6%13%26%18%1
1312
16th to endNight
37%416%29%11%
1418
August1st to 15thNight
38%6%17%24%12%
1562
16th to endNight
34%5%19%30%9%
1800
September1st to 15thNight
43%413%26%11%
1800
16th to endNight
40%414%32%7%
1981
October1st to 15thNight
50%410%22%11%
2160
16th to endNight
61%5%11%16%4
2361
November1st to 15thNight
56%412%16%8%
2608
16th to endNight
68%311%13%3
2730
December1st to 15thNight
71%310%10%3
2574
16th to endNight
71%39%9%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
38%10%31%16%3
60
16th to endDay
37%7%29%17%7%
78
February1st to 15thDay
31%17%33%16%1
90
16th to endDay
37%10%28%21%1
128
March1st to 15thDay
26%14%31%20%5%
270
16th to endDay
19%17%27%23%9%2
288
April1st to 15thDay
30%13%27%19%7%1
270
16th to endDay
30%11%24%15%13%4
270
May1st to 15thDay
35%7%23%19%9%4
288
16th to endDay
21%13%32%19%10%3
331
June1st to 15thDay
27%6%29%24%10%1
315
16th to endDay
18%10%31%22%15%2
446
July1st to 15thDay
17%5%31%28%13%3
347
16th to endDay
13%430%29%17%4
326
August1st to 15thDay
14%5%24%29%18%7%
313
16th to endDay
18%5%21%24%19%10%
332
September1st to 15thDay
21%421%21%16%13%
315
16th to endDay
19%7%21%23%18%9%
314
October1st to 15thDay
24%11%26%22%14%1
315
16th to endDay
34%14%22%19%7%
322
November1st to 15thDay
23%12%26%23%12%1
141
16th to endDay
40%12%33%10%31
90
December1st to 15thDay
20%16%35%17%7%1
67
16th to endDay
40%17%34%6%1
64
January1st to 15thNight
30%10%28%22%7%
720
16th to endNight
22%11%27%28%8%1
768
February1st to 15thNight
21%12%33%24%6%1
704
16th to endNight
24%14%29%24%6%
631
March1st to 15thNight
27%13%27%25%4
720
16th to endNight
20%14%26%26%11%
768
April1st to 15thNight
28%11%27%27%5%
718
16th to endNight
24%9%28%25%11%
603
May1st to 15thNight
25%427%30%11%
366
16th to endNight
18%8%26%34%11%
375
June1st to 15thNight
20%5%28%33%11%1
360
16th to endNight
17%6%23%38%14%1
360
July1st to 15thNight
12%324%40%17%2
340
16th to endNight
11%221%42%20%1
376
August1st to 15thNight
14%416%35%25%2
491
16th to endNight
13%322%36%22%1
654
September1st to 15thNight
19%5%21%29%21%2
720
16th to endNight
18%5%18%30%23%2
717
October1st to 15thNight
26%7%25%26%12%
720
16th to endNight
34%9%23%24%7%
768
November1st to 15thNight
24%11%25%26%11%
760
16th to endNight
33%13%24%20%7%
780
December1st to 15thNight
32%13%27%21%4
736
16th to endNight
36%10%24%21%5%1
768
Page generated at 2017-12-05 10:19:05. Version ac04

Copyright 2017 A. Danko


Deep River Clear Sky Chart |Charts Home