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 2017-04-08.

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
31%
14186
12%
45317
8%
14157
36%
14157
16%
32897

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%
2074
10%
768
39%
768
22%
1425
April1st to 15thNight
27%
690
16%
1726
6%
690
32%
690
19%
1288
April16th to endNight
35%
553
17%
1543
9%
553
41%
553
23%
1071
May1st to 15thNight
34%
336
18%
1326
17%
336
42%
336
18%
856
May16th to endNight
39%
342
13%
1369
12%
342
50%
342
19%
845
June1st to 15thNight
35%
330
8%
1320
7%
330
42%
330
16%
883
June16th to endNight
47%
330
9%
1194
10%
330
52%
330
21%
755
July1st to 15thNight
50%
310
15%
1196
18%
310
55%
310
29%
659
July16th to endNight
57%
348
12%
1306
13%
326
61%
326
25%
747
August1st to 15thNight
53%
450
15%
1431
12%
448
57%
448
28%
892
August16th to endNight
54%
599
17%
1649
10%
599
59%
599
33%
1036
September1st to 15thNight
43%
660
15%
1650
7%
660
46%
660
29%
1140
September16th to endNight
47%
657
18%
1816
11%
657
51%
657
29%
1184
October1st to 15thNight
31%
660
16%
1980
11%
660
38%
660
19%
1412
October16th to endNight
26%
704
10%
2164
7%
704
32%
704
12%
1703
November1st to 15thNight
29%
700
14%
2402
12%
700
35%
700
14%
1745
November16th to endNight
21%
720
8%
2520
5%
720
25%
720
9%
2004
December1st to 15thNight
17%
720
6%
2520
3%
720
22%
720
7%
2071
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%
45940
Night
18%11%47%6%34445%30%
45487
TransparencyDay
54%411%19%9%1
45628
Night
55%411%18%9%
45317
SeeingDay
23%9%27%22%12%4
4882
Night
24%9%25%27%11%
14189

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%16%6%8%6%2433424%
1468
March1st to 15thDay
17%14%5%8%5%3335%5%26%
1903
16th to endDay
13%8%47%5%34446%38%
2149
April1st to 15thDay
24%11%46%423235%30%
2062
16th to endDay
22%8%25%5%23235%37%
2098
May1st to 15thDay
19%9%36%6%34445%32%
2294
16th to endDay
18%6%45%5%34446%35%
2394
June1st to 15thDay
21%7%46%6%35%5%5%6%26%
2310
16th to endDay
16%5%25%6%36%5%6%8%34%
2431
July1st to 15thDay
16%436%6%45%5%6%7%34%
2349
16th to endDay
13%5%36%5%46%5%7%8%33%
2458
August1st to 15thDay
14%7%36%6%45%45%7%32%
2187
16th to endDay
13%6%25%5%36%5%5%9%34%
2190
September1st to 15thDay
18%7%25%5%335%47%35%
1980
16th to endDay
20%7%245%14335%41%
1813
October1st to 15thDay
23%9%37%5%34345%29%
1650
16th to endDay
31%13%45%423345%20%
1708
November1st to 15thDay
19%11%47%43445%5%29%
1453
16th to endDay
28%17%6%7%43433317%
1440
December1st to 15thDay
21%18%6%9%7%35%43413%
1440
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%42334440%
2074
April1st to 15thNight
22%10%35%434345%31%
1726
16th to endNight
20%8%24424446%36%
1543
May1st to 15thNight
21%6%27%5%12336%38%
1326
16th to endNight
15%6%35%5%35%35%7%38%
1367
June1st to 15thNight
19%7%36%5%35%45%6%33%
1320
16th to endNight
13%4345%35%7%6%9%36%
1194
July1st to 15thNight
11%42433445%7%47%
1276
16th to endNight
11%324335%47%9%42%
1402
August1st to 15thNight
13%5%145%25%5%6%7%42%
1441
16th to endNight
10%4245%3445%9%44%
1649
September1st to 15thNight
17%6%35%423347%40%
1650
16th to endNight
17%6%25%423336%44%
1816
October1st to 15thNight
23%9%26%42334435%
1980
16th to endNight
28%11%36%6%3435%422%
2164
November1st to 15thNight
20%10%37%6%25%345%29%
2402
16th to endNight
27%15%5%8%6%2233321%
2520
December1st to 15thNight
23%18%6%9%5%3433317%
2520
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%
1468
March1st to 15thDay
59%311%17%8%1
1914
16th to endDay
46%49%20%15%4
2149
April1st to 15thDay
56%27%18%11%3
2062
16th to endDay
50%25%21%16%3
2098
May1st to 15thDay
52%39%17%15%2
2294
16th to endDay
48%5%9%22%11%2
2398
June1st to 15thDay
55%411%18%9%
2310
16th to endDay
45%6%11%22%12%1
2431
July1st to 15thDay
42%5%12%26%11%1
2200
16th to endDay
46%5%14%23%9%
2291
August1st to 15thDay
47%5%16%19%10%
2173
16th to endDay
43%6%15%25%8%
2190
September1st to 15thDay
46%6%14%23%8%
1980
16th to endDay
46%313%29%7%
1813
October1st to 15thDay
55%412%17%9%
1650
16th to endDay
66%411%13%3
1708
November1st to 15thDay
54%5%14%17%7%
1453
16th to endDay
71%310%9%4
1440
December1st to 15thDay
72%49%11%2
1440
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
2074
April1st to 15thNight
54%37%19%12%2
1726
16th to endNight
48%37%21%15%3
1543
May1st to 15thNight
48%46%20%17%3
1326
16th to endNight
44%411%22%14%2
1369
June1st to 15thNight
49%5%11%21%10%
1320
16th to endNight
40%8%13%23%13%
1194
July1st to 15thNight
32%6%13%27%19%1
1196
16th to endNight
37%416%28%11%
1306
August1st to 15thNight
37%6%17%24%13%
1431
16th to endNight
35%6%19%28%10%
1649
September1st to 15thNight
44%414%26%10%
1650
16th to endNight
41%314%31%7%
1816
October1st to 15thNight
52%410%21%11%
1980
16th to endNight
62%5%11%15%5%
2164
November1st to 15thNight
56%412%17%8%
2402
16th to endNight
67%311%13%3
2520
December1st to 15thNight
71%310%10%3
2520
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%11%29%20%1
127
March1st to 15thDay
26%14%31%20%5%
270
16th to endDay
19%17%27%23%9%2
288
April1st to 15thDay
29%15%25%20%7%2
240
16th to endDay
26%10%23%17%17%5%
210
May1st to 15thDay
28%7%26%20%9%6%
228
16th to endDay
20%11%31%21%11%3
267
June1st to 15thDay
29%5%27%24%11%2
255
16th to endDay
15%9%30%24%16%3
376
July1st to 15thDay
17%5%29%29%13%4
284
16th to endDay
12%5%32%27%18%4
270
August1st to 15thDay
15%5%24%28%18%8%
253
16th to endDay
17%5%22%25%19%10%
268
September1st to 15thDay
24%420%20%16%13%
255
16th to endDay
20%8%24%22%15%8%
254
October1st to 15thDay
25%10%25%22%15%1
255
16th to endDay
36%11%24%18%7%1
263
November1st to 15thDay
18%11%28%27%13%
107
16th to endDay
41%8%28%15%5%1
60
December1st to 15thDay
18%18%36%16%8%1
60
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
29%11%27%26%5%
690
16th to endNight
24%8%26%27%12%
553
May1st to 15thNight
23%428%30%12%
336
16th to endNight
18%6%27%34%11%
343
June1st to 15thNight
20%6%28%32%11%
330
16th to endNight
16%6%23%38%14%1
330
July1st to 15thNight
12%325%39%17%2
310
16th to endNight
11%221%42%20%1
348
August1st to 15thNight
15%417%34%25%2
450
16th to endNight
13%223%37%21%1
599
September1st to 15thNight
20%5%22%28%20%2
660
16th to endNight
20%5%20%30%21%2
657
October1st to 15thNight
27%8%25%26%11%
660
16th to endNight
35%8%22%25%8%
704
November1st to 15thNight
24%10%25%27%11%
700
16th to endNight
33%13%24%20%7%
720
December1st to 15thNight
32%14%27%21%4
720
16th to endNight
36%10%24%21%5%1
768
Page generated at 2017-04-09 06:54:16. Version ac04

Copyright 2017 A. Danko


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