Station 44007 (LLNR 75) - PORTLAND - 12 NM Southeast of Portland,ME Image indicating link to RSS feed of recent meteorological observations for station 44007

East Hue and Cry Rock Lighted Buoy 1


Conditions at 44007 as of
(1:00 am EST)
0600 GMT on 12/25/2025:
     

Click on the graph icon in the table below to see a time series plot of the last five days of that observation.

5-day plot - Wind Direction Wind Direction (WDIR): N ( 350 deg true )
5-day plot - Wind Speed Wind Speed (WSPD): 3.9 kts
5-day plot - Wind Gust Wind Gust (GST): 9.7 kts
5-day plot - Atmospheric Pressure Atmospheric Pressure (PRES):30.17 in
5-day plot - Pressure Tendency Pressure Tendency (PTDY):-0.07 in ( Falling )
5-day plot - Air Temperature Air Temperature (ATMP): 28.6 °F
5-day plot - Water Temperature Water Temperature (WTMP): 42.4 °F
5-day plot - Dew Point Dew Point (DEWP): 23.4 °F
5-day plot - Ice Accretion Ice Accretion (ICE): 0.00 in per hour
5-day plot - Wind Chill Wind Chill (CHILL): 23.5 °F
5-day plot - Wind Speed at 10 Meters Wind Speed at 10 meters (WSPD10M): 3.9 kts
5-day plot - Wind Speed at 20 Meters Wind Speed at 20 meters (WSPD20M): 3.9 kts
5-day plot -  Wind Speed, Wind Gust and Atmospheric Pressure Combined plot of Wind Speed, Gust, and Air Pressure
Supplemental Measurements
Highest 1-minute Wind Speed
Time (EST)5-day plot - 1-Minute Wind Speed WSPD 5-day plot - 1-Minute Wind Direction WDIR
12:59 am 5.8 kts-
Previous observations
TIME
(EST)
5-day plot - Wind Direction
WDIR
 
5-day plot - Wind Speed
WSPD
kts
5-day plot - Wind Gust
GST
kts
5-day plot - Wave Height
WVHT
ft
5-day plot - Dominant Wave Period
DPD
sec
5-day plot - Average Wave Period
APD
sec
5-day plot - Mean Wave Direction
MWD
 
5-day plot - Atmospheric Pressure
PRES
in
5-day plot - Pressure Tendency
PTDY
in
5-day plot - Air Temperature
ATMP
°F
5-day plot - Water Temperature
WTMP
°F
5-day plot - Dew Point
DEWP
°F
5-day plot - Salinity
SAL
psu
5-day plot - Visibility
VIS
nmi
5-day plot - Tide (above MLLW)
TIDE
ft
2025-12-25 12:50 amNNE 1.9 5.8 5.6 86.6ESE30.17- 28.4 42.4 23.4---
2025-12-25 12:40 am N 3.9 5.8----30.17- 28.2 42.4 23.0---
2025-12-25 12:30 am N 3.9 5.8----30.18- 28.4 42.4 23.5---
2025-12-25 12:20 amWNW 3.9 7.8 6.2 96.8ESE30.18- 28.2 42.4 23.2---
2025-12-25 12:10 amNNW 1.9 5.8----30.18- 28.0 42.4 23.0---
2025-12-25 12:00 amENE 1.9 3.9----30.18-0.08 27.9 42.4 23.4---
2025-12-24 11:50 pmESE 1.9 5.8 6.6 87.0 E30.18- 27.7 42.4 23.0---
2025-12-24 11:40 pm W 1.9 3.9----30.19- 27.7 42.4 22.8---
2025-12-24 11:30 pm N 1.9 3.9----30.20- 27.5 42.4 22.5---
2025-12-24 11:20 pmNNE 1.9 3.9 6.2 86.6ESE30.21- 27.5 42.4 22.5---
2025-12-24 11:10 pm N 1.9 5.8----30.21- 27.5 42.4 22.6---
2025-12-24 11:00 pmNNE 3.9 5.8----30.22-0.04 27.5 42.4 22.6---
2025-12-24 10:50 pm NE 3.9 11.7 7.2 97.0ESE30.22- 27.5 42.4 22.8---
2025-12-24 10:40 pmNNE 3.9 9.7----30.22- 27.3 42.4 22.6---
2025-12-24 10:30 pmNNE 5.8 7.8----30.23- 27.3 42.4 22.5---
2025-12-24 10:20 pm N 5.8 7.8 6.6 96.7ESE30.24- 27.3 42.4 22.5---
2025-12-24 10:10 pm N 5.8 7.8----30.24- 27.0 42.3 22.1---
2025-12-24 10:00 pm NE 3.9 7.8----30.25-0.02 27.0 42.4 22.5---
2025-12-24 09:50 pm N 5.8 7.8 6.2 86.4ESE30.25- 27.1 42.3 22.3---
2025-12-24 09:40 pm N 5.8 9.7----30.26- 27.1 42.3 22.3---
2025-12-24 09:30 pm N 5.8 9.7----30.27- 27.3 42.3 22.8---
2025-12-24 09:20 pmNNE 5.8 7.8 7.9 97.1ESE30.27- 27.3 42.1 23.2---
2025-12-24 09:10 pmNNE 7.8 11.7----30.27- 26.8 42.1 22.6---
2025-12-24 09:00 pm NE 7.8 13.6----30.26+0.02 26.6 42.1 23.0---
2025-12-24 08:50 pm NE 9.7 15.5 6.9 96.8 E30.25- 26.6 42.3 23.7---
2025-12-24 08:40 pm NE 9.7 13.6----30.24- 26.2 42.3 23.4---
2025-12-24 08:30 pm NE 11.7 15.5----30.25- 26.2 42.3 23.5---
2025-12-24 08:20 pm NE 11.7 15.5 7.5 96.9ESE30.25- 26.1 42.3 23.0---
2025-12-24 08:10 pmNNE 13.6 15.5----30.25- 26.1 42.3 23.0---
2025-12-24 08:00 pmNNE 11.7 15.5----30.26+0.03 25.9 42.4 23.0---
2025-12-24 07:50 pmNNE 11.7 15.5 8.2 97.2ESE30.27- 25.9 42.4 23.0---
2025-12-24 07:40 pmNNE 13.6 15.5----30.27- 26.1 42.4 23.0---
2025-12-24 07:30 pm N 11.7 15.5----30.27- 26.2 42.4 23.4---
2025-12-24 07:20 pm N 11.7 15.5 7.9 86.8ESE30.28- 26.1 42.4 22.8---
2025-12-24 07:10 pm N 11.7 15.5----30.28- 26.4 42.4 23.4---
2025-12-24 07:00 pm N 11.7 15.5----30.27+0.07 26.2 42.4 23.2---
2025-12-24 06:50 pm N 13.6 17.5 8.5 97.1ESE30.26- 26.4 42.4 23.5---
2025-12-24 06:40 pm N 13.6 17.5----30.26- 26.8 42.4 24.1---
2025-12-24 06:30 pm N 13.6 17.5----30.26- 26.8 42.4 24.1---
2025-12-24 06:20 pmNNE 13.6 17.5 7.5 96.5ESE30.25- 26.8 42.4 24.1---
2025-12-24 06:10 pmNNE 13.6 15.5----30.25- 26.8 42.4 24.3---
2025-12-24 06:00 pmNNE 13.6 17.5----30.24+0.08 27.0 42.4 24.8---
2025-12-24 05:50 pm N 13.6 17.5 7.9 106.9ESE30.24- 26.2 42.4 23.9---
2025-12-24 05:40 pm N 13.6 17.5----30.24- 26.4 42.4 24.3---
2025-12-24 05:30 pm N 13.6 17.5----30.24- 26.2 42.6 23.9---
2025-12-24 05:20 pm N 15.5 17.5 8.9 96.9ESE30.24- 26.4 42.6 24.1---
2025-12-24 05:10 pm N 15.5 19.4----30.23- 26.2 42.6 24.1---
2025-12-24 05:00 pm N 15.5 19.4----30.23+0.11 26.2 42.6 24.1---
2025-12-24 04:50 pm N 15.5 19.4 8.2 106.6ESE30.22- 26.2 42.6 24.3---
2025-12-24 04:40 pm N 15.5 19.4----30.22- 26.4 42.6 24.6---
2025-12-24 04:30 pm N 15.5 21.4----30.20- 26.2 42.6 24.4---
2025-12-24 04:20 pm N 15.5 21.4 8.2 96.5ESE30.20- 26.4 42.6 24.8---
2025-12-24 04:10 pm N 15.5 21.4 8.2-6.5ESE30.21- 26.2 42.6 24.4---
2025-12-24 04:00 pm N 17.5 23.3----30.21+0.12 26.2 42.6 24.6---
2025-12-24 03:50 pm N 17.5 25.3 9.2 96.8ESE30.20- 26.2 42.8 24.6---
2025-12-24 03:40 pm N 17.5 23.3----30.19- 26.1 43.0 24.4---
2025-12-24 03:30 pm N 17.5 25.3----30.19- 26.1 43.2 24.4---
2025-12-24 03:20 pm N 19.4 25.3 8.9 96.5 E30.18- 26.1 43.2 24.6---
2025-12-24 03:10 pm N 19.4 25.3 8.9-6.5 E30.17- 25.7 43.2 24.3---
2025-12-24 03:00 pm N 19.4 27.2----30.16+0.12 25.7 43.2 24.4---
2025-12-24 02:50 pm N 21.4 27.2 8.9 96.4ESE30.16- 25.5 43.2 24.3---
2025-12-24 02:40 pm N 21.4 27.2 8.9-6.4ESE30.15- 25.7 43.2 24.4---
2025-12-24 02:30 pm N 21.4 27.2----30.15- 25.5 43.2 24.3---
2025-12-24 02:20 pm N 21.4 27.2 9.5 86.4 E30.14- 25.7 43.2 24.6---
2025-12-24 02:10 pm N 21.4 27.2----30.14- 25.5 43.2 24.4---
2025-12-24 02:00 pm N 23.3 27.2----30.12+0.12 25.5 43.3 24.4---
2025-12-24 01:50 pm N 23.3 29.1 10.8 96.8ESE30.11- 25.5 43.3 24.4---
2025-12-24 01:40 pm N 23.3 31.1----30.11- 25.3 43.3 24.1---
2025-12-24 01:30 pm N 23.3 31.1----30.10- 25.3 43.3 24.3---
2025-12-24 01:20 pm N 23.3 31.1 9.5 96.4ESE30.10- 25.3 43.3 24.3---
2025-12-24 01:10 pm N 23.3 29.1 9.5-6.4ESE30.09- 25.2 43.3 24.1---
2025-12-24 01:00 pm N 23.3 31.1----30.09+0.11 25.0 43.5 23.9---
2025-12-24 12:50 pm N 23.3 31.1 9.2 96.2 E30.08- 25.2 43.5 24.1---
2025-12-24 12:40 pm N 23.3 31.1----30.07- 25.2 43.5 24.3---
2025-12-24 12:30 pm N 23.3 31.1----30.07- 25.2 43.5 24.1---
2025-12-24 12:20 pm N 23.3 29.1 9.8 86.4 E30.06- 25.2 43.3 24.3---
2025-12-24 12:10 pm N 23.3 29.1----30.05- 25.0 43.3 24.1---
2025-12-24 12:00 pm N 23.3 31.1----30.04+0.13 25.2 43.3 24.3---
2025-12-24 11:50 am N 21.4 31.1 10.2 96.4 E30.04- 25.7 43.3 25.0---
2025-12-24 11:40 am N 25.3 35.0----30.03- 25.5 43.3 24.8---
2025-12-24 11:30 am N 23.3 33.0----30.03- 25.5 43.3 24.8---
2025-12-24 11:20 am N 23.3 35.0 9.8 96.0ESE30.02- 25.7 43.3 25.0---
2025-12-24 11:10 am N 23.3 29.1----30.01- 25.9 43.3 25.2---
2025-12-24 11:00 am N 25.3 31.1----30.01+0.16 26.2 43.3 25.5---
2025-12-24 10:50 am N 25.3 31.1 9.8 96.1 E30.00- 26.1 43.2 25.3---
2025-12-24 10:40 am N 25.3 29.1----30.00- 26.2 43.2 25.5---
2025-12-24 10:30 am N 25.3 31.1----29.99- 26.1 43.2 25.3---
2025-12-24 10:20 am N 25.3 31.1 9.5 85.9 E29.98- 26.1 43.2 25.3---
2025-12-24 10:10 am N 25.3 31.1----29.98- 26.4 43.2 25.7---
2025-12-24 10:00 am N 25.3 31.1----29.98+0.20 26.2 43.0 25.5---
2025-12-24 09:50 am N 25.3 33.0 9.5 85.9 E29.98- 26.2 43.0 25.5---
2025-12-24 09:40 am N 25.3 33.0----29.97- 26.2 43.0 25.5---
2025-12-24 09:30 am N 25.3 31.1----29.96- 26.8 43.2 26.1---
2025-12-24 09:20 am N 25.3 31.1 9.5 86.0 E29.94- 27.3 43.2 26.6---
2025-12-24 09:10 am N 25.3 31.1 9.5-6.0 E29.93- 27.7 43.2 27.0---
2025-12-24 09:00 am N 25.3 31.1----29.91+0.16 27.7 43.3 27.0---
2025-12-24 08:50 am N 25.3 31.1 9.2 85.7ENE29.90- 27.9 43.3 27.1---
2025-12-24 08:40 am N 27.2 31.1----29.88- 28.0 43.3 27.3---
2025-12-24 08:30 am N 27.2 33.0----29.88- 28.4 43.3 27.7---
2025-12-24 08:20 am N 27.2 33.0 8.9 85.5 E29.87- 28.8 43.5 28.0---
2025-12-24 08:10 am N 25.3 33.0----29.86- 28.9 43.5 28.2---
2025-12-24 08:00 am N 27.2 33.0----29.84+0.11 29.1 43.3 28.4---
2025-12-24 07:50 am N 27.2 35.0 7.5 85.2 E29.83- 29.7 43.3 28.9---
2025-12-24 07:40 am N 27.2 35.0----29.82- 29.7 43.5 28.9---
2025-12-24 07:30 am N 29.1 35.0----29.80- 29.7 43.7 28.9---
2025-12-24 07:20 am N 27.2 33.0 6.6 74.9 E29.79- 29.8 43.9 29.1---
2025-12-24 07:10 am N 27.2 35.0----29.79- 29.7 43.9 28.9---
2025-12-24 07:00 amNNW 29.1 35.0----29.78+0.04 29.7 43.9 28.9---
2025-12-24 06:50 amNNW 27.2 35.0 6.6 74.9 E29.77- 29.8 43.9 29.1---
2025-12-24 06:40 amNNW 27.2 33.0----29.76- 30.2 43.9 29.5---
2025-12-24 06:30 amNNW 25.3 31.1----29.76- 29.8 43.9 29.1---
2025-12-24 06:20 amNNW 25.3 29.1 6.2 75.0ESE29.75- 29.5 43.9 28.8---
2025-12-24 06:10 amNNW 23.3 29.1----29.75- 29.5 43.9 28.8---
2025-12-24 06:00 amNNW 23.3 31.1----29.75-0.01 29.5 43.9 28.8---
2025-12-24 05:50 amNNW 23.3 29.1 5.6 74.8 E29.75- 29.5 44.1 28.8---
2025-12-24 05:40 amNNW 23.3 27.2----29.75- 29.5 43.9 28.8---
2025-12-24 05:30 amNNW 21.4 25.3----29.75- 29.5 44.1 28.8---
2025-12-24 05:20 amNNW 21.4 25.3 5.6 65.0ESE29.74- 29.5 44.1 28.8---
2025-12-24 05:10 amNNW 21.4 27.2----29.74- 29.7 44.1 28.9---
2025-12-24 05:00 amNNW 21.4 25.3----29.74-0.05 29.7 44.1 28.9---
2025-12-24 04:50 amNNW 19.4 23.3 5.2 64.8ESE29.73- 29.8 44.1 29.1---
2025-12-24 04:40 amNNW 19.4 23.3----29.74- 30.0 44.1 29.3---
2025-12-24 04:30 amNNW 19.4 23.3----29.74- 30.4 44.1 29.7---
2025-12-24 04:20 amNNW 17.5 21.4 5.2 74.9 E29.74- 30.9 44.1 30.2---
2025-12-24 04:10 amNNW 17.5 21.4----29.74- 30.9 44.1 30.2---
2025-12-24 04:00 amNNW 15.5 19.4----29.74-0.07 31.6- 30.9---
2025-12-24 03:50 am N 15.5 19.4 4.9 65.0ESE29.74- 32.0 44.1 31.3---
2025-12-24 03:40 am N 15.5 19.4 4.9-5.0ESE29.75- 32.4 44.1 31.6---
2025-12-24 03:30 am N 13.6 19.4----29.75- 33.1 44.2 32.4---
2025-12-24 03:20 am N 11.7 15.5 4.6 64.9ESE29.75- 34.0 44.2 33.3---
2025-12-24 03:10 am N 9.7 13.6----29.76- 34.2 44.2 33.3---
2025-12-24 03:00 am N 7.8 9.7----29.76-0.09 34.3 44.2 33.4---
2025-12-24 02:50 am N 7.8 9.7 4.6 64.9ESE29.77- 34.7 44.2 33.8---
2025-12-24 02:40 am N 7.8 11.7----29.77- 34.5 44.2 33.4---
2025-12-24 02:30 am N 7.8 9.7----29.78- 34.9 44.2 33.8---
2025-12-24 02:20 amNNW 7.8 9.7 4.6 65.0ESE29.78- 35.2 44.2 34.2---
2025-12-24 02:10 amNNW 5.8 9.7----29.79- 35.2 44.2 34.0---
2025-12-24 02:00 am NW 7.8 9.7----29.79-0.10 35.6 44.4 34.3---
2025-12-24 01:50 am NW 5.8 9.7 3.9 64.5ESE29.79- 36.0 44.4 34.5---
2025-12-24 01:40 am NW 5.8 9.7 3.9-4.5ESE29.80- 36.1 44.4 34.5---
2025-12-24 01:30 amWNW 5.8 9.7----29.80- 36.3 44.4 34.7---
2025-12-24 01:20 am W 7.8 11.7 4.3 64.6ESE29.80- 36.5 44.4 34.7---
2025-12-24 01:10 amWSW 7.8 11.7----29.81- 36.7 44.4 35.1---
2025-12-24 01:00 amWSW 7.8 11.7----29.81-0.11 36.9 44.4 35.2---
2025-12-24 12:50 amWSW 7.8 9.7 3.9 64.5 SE29.82- 37.0 44.4 35.4---

Wave Summary
for 44007 as of (12:40 am EST)
0540 GMT on 12/25/2025:

These wave data are displayed in rounded times.

     

Click on the graph icon in the table below to see a time series plot of the last five days of that observation.

5-day plot - Significant Wave Height Significant Wave Height (WVHT): 5.6 ft
5-day plot - Swell Height Swell Height (SwH): 5.6 ft
5-day plot - Swell Period Swell Period (SwP): 8.3 sec
5-day plot - Swell Direction Swell Direction (SwD):ESE
5-day plot - Wind Wave Height Wind Wave Height (WWH): 1.3 ft
5-day plot - Wind Wave Period Wind Wave Period (WWP): 4.0 sec
5-day plot - Wind Wave Direction Wind Wave Direction (WWD): E
5-day plot - Wave Steepness Wave Steepness (STEEPNESS): AVERAGE
5-day plot - Average Wave Period Average Wave Period (APD): 6.6 sec
Previous observations
TIME
(EST)
5-day plot - Wave Height
WVHT
ft
5-day plot - Swell Height
SwH
ft
5-day plot - Swell Period
SwP
sec
5-day plot - Swell Direction
SwD
 
5-day plot - Wind Wave Height
WWH
ft
5-day plot - Wind Wave Period
WWP
sec
5-day plot - Wind Wave Direction
WWD
 
5-day plot - Wave Steepness
STEEPNESS
 
5-day plot - Average Wave Period
APD
sec
2025-12-25 12:10 am 6.2 5.9 9.1ESE 1.3 4.0 E AVERAGE 6.8
2025-12-24 11:40 pm 6.6 6.6 8.3 E 1.3 3.8 E AVERAGE 7.0
2025-12-24 11:10 pm 6.2 6.2 8.3ESE 1.6 3.8 E AVERAGE 6.6
2025-12-24 10:40 pm 7.2 6.9 9.1ESE 1.3 3.7 E AVERAGE 7.0
2025-12-24 10:10 pm 6.6 6.6 9.1ESE 1.6 3.3 E AVERAGE 6.7
2025-12-24 09:40 pm 6.2 5.9 8.3ESE 1.6 3.6 ENE AVERAGE 6.4
2025-12-24 09:10 pm 7.9 7.9 9.1ESE 1.3 3.8 E AVERAGE 7.1
2025-12-24 08:40 pm 6.9 6.6 9.1 E 2.0 4.8 E AVERAGE 6.8
2025-12-24 08:10 pm 7.5 6.9 9.1ESE 3.0 5.3 E AVERAGE 6.9
2025-12-24 07:40 pm 8.2 7.5 9.1ESE 3.3 6.2 E AVERAGE 7.2
2025-12-24 07:10 pm 7.9 7.2 8.3ESE 3.3 5.6 E STEEP 6.8
2025-12-24 06:40 pm 8.5 7.9 9.1ESE 3.3 5.6 E AVERAGE 7.1
2025-12-24 06:10 pm 7.5 6.6 9.1ESE 3.6 5.0 E AVERAGE 6.5
2025-12-24 05:40 pm 7.9 7.2 10.0ESE 3.3 6.2 ESE AVERAGE 6.9
2025-12-24 05:10 pm 8.9 8.2 9.1ESE 3.6 5.3 E AVERAGE 6.9
2025-12-24 04:40 pm 8.2 7.5 10.0ESE 3.6 5.6 E AVERAGE 6.6
2025-12-24 04:10 pm 8.2 6.9 9.1ESE 4.3 6.7 E AVERAGE 6.5
2025-12-24 03:40 pm 9.2 8.2 9.1ESE 4.6 6.7 E AVERAGE 6.8
2025-12-24 03:10 pm 8.9 7.5 9.1 E 4.6 6.2 E AVERAGE 6.5
2025-12-24 02:40 pm 8.9 7.9 9.1ESE 4.3 6.2 E AVERAGE 6.4
2025-12-24 02:10 pm 9.5 8.2 8.3 E 4.3 5.0 ENE STEEP 6.4
2025-12-24 01:40 pm 10.8 9.5 9.1ESE 4.9 3.8 NNE STEEP 6.8
2025-12-24 01:10 pm 9.5 8.2 9.1ESE 5.2 5.0 ENE STEEP 6.4
2025-12-24 12:40 pm 9.2 7.9 9.1 E 4.9 5.9 E AVERAGE 6.2
2025-12-24 12:10 pm 9.8 7.2 8.3 E 6.6 5.6 E STEEP 6.4
2025-12-24 11:40 am 10.2 8.2 9.1 E 6.2 7.1 E STEEP 6.4
2025-12-24 11:10 am 9.8------ STEEP 6.0
2025-12-24 10:40 am 9.8------ STEEP 6.1
2025-12-24 10:10 am 9.5------ STEEP 5.9
2025-12-24 09:40 am 9.5------ STEEP 5.9
2025-12-24 09:10 am 9.5------ STEEP 6.0
2025-12-24 08:40 am 9.2------ STEEP 5.7
2025-12-24 08:10 am 8.9------ STEEP 5.5
2025-12-24 07:40 am 7.5------ STEEP 5.2
2025-12-24 07:10 am 6.6------ STEEP 4.9
2025-12-24 06:40 am 6.6------ STEEP 4.9
2025-12-24 06:10 am 6.2------ STEEP 5.0
2025-12-24 05:40 am 5.6------ STEEP 4.8
2025-12-24 05:10 am 5.6------VERY_STEEP 5.0
2025-12-24 04:40 am 5.2 3.9 6.2ESE 3.3 2.7 N STEEP 4.8
2025-12-24 04:10 am 5.2 0.0-- 5.2 6.7 E STEEP 4.9
2025-12-24 03:40 am 4.9 0.7 11.4 W 4.9 5.9 ESEVERY_STEEP 5.0
2025-12-24 03:10 am 4.6 3.9 5.6ESE 2.3 4.5 SEVERY_STEEP 4.9
2025-12-24 02:40 am 4.6 4.3 6.2ESE 1.6 3.8 SSE STEEP 4.9
2025-12-24 02:10 am 4.6 4.3 5.9ESE 1.6 3.8 SSEVERY_STEEP 5.0
2025-12-24 01:40 am 3.9 3.6 5.6ESE 1.6 3.8 SSEVERY_STEEP 4.5
2025-12-24 01:10 am 4.3 3.9 5.6ESE 2.0 4.0 SEVERY_STEEP 4.6

Plot icon Plot of wave energy versus frequency (and period)