| R | Rayleigh | - | Business and Finance |
| R | Roentger | - | Business and Finance |
| R&D | Research And Development | - | Business and Finance |
| R&D | Research & Development | - | Business and Finance |
| R-Z RELATIONSHIP | R = Precipitation Rate | - | Business and Finance |
| R-Z RELATIONSHIP | R = Precipitation Rate | - | Business and Finance |
| R/T | Receiver/Transmitter | - | Business and Finance |
| R/T | Reciever/Transmitter | - | Business and Finance |
| RA | Radio Antenna | - | Business and Finance |
| RA | Radio Active | - | Business and Finance |
| RA# | Raleigh Number | - | Business and Finance |
| RAAF | Royal Australian Air Force | - | Business and Finance |
| RACOON | Radiation Controlled Balloon | - | Business and Finance |
| RADARSAT | Radar Satellite | - | Business and Finance |
| RADEX | Radar Experiment | - | Business and Finance |
| RADM | Regional Acid Deposition Model | - | Business and Finance |
| RAF | Research Aviation Facility | - | Business and Finance |
| RAFS | Regional Analysis And Forecast System | - | Business and Finance |
| RAG | Resource Accounting Group | - | Business and Finance |
| RAID | Redundant Arrays Of Inexpensive Disks | - | Business and Finance |
| RALI | Resource And Land Information | - | Business and Finance |
| RAM | Random Access Memory | - | Business and Finance |
| RAM | Responsibility Assignment Matrix | - | Business and Finance |
| RAM | Research Application Module | - | Business and Finance |
| RAM | Rad Academica De Mexico | - | Business and Finance |
| RAMOS | Remote Automatic Meteorological Observing Station | - | Business and Finance |
| RAMS | Random Access Measurement System | - | Business and Finance |
| RAMS | Remote Aerosol-Mapping System | - | Business and Finance |
| RAMS | Regional Atmospheric Modeling System | - | Business and Finance |
| RAND OR RAND | Research And Development | - | Business and Finance |
| RANN | Research Applied To National Needs | - | Business and Finance |
| RAOB | Radiosonde Observation | - | Business and Finance |
| RAOBS | Radiosonde Observations | - | Business and Finance |
| RAP | Research Applications Program | - | Business and Finance |
| RAP | Remedial Action Plan | - | Business and Finance |
| RAPB | Regional Analysis And Prediction Branch | - | Business and Finance |
| RAPS | Real-Time Analysis And Prediction Of Storms | - | Business and Finance |
| RAPS-92 | Real-Time Analysis And Prediction Of Storms-1992 | - | Business and Finance |
| RAPTSTM WX | Research Applications Program Thunderstorm Weather | - | Business and Finance |
| RAS | Retrospective Analysis System | - | Business and Finance |
| RAS | Royal Astronomical Society | - | Business and Finance |
| RASS | Radio Acoustic Sounding System | - | Business and Finance |
| RASTER | (Remote) ASTER | - | Business and Finance |
| RATS | Real-time Aircraft Tracking System | - | Business and Finance |
| RAWINS | Radio Wind Measurements | - | Business and Finance |
| RAWPG | Regional Aviation Weather Products Generator | - | Business and Finance |
| RAWS | Remote Automatic Weather Station | - | Business and Finance |
| RBV | Return Beam Vidicon | - | Business and Finance |
| RCA | Request For Contract Action | - | Business and Finance |
| RCAG | Remote-controlled Air-to-ground | - | Business and Finance |
| RCHO | Aldehydes | - | Business and Finance |
| RCM | WSR-88D Radar Coded Message | - | Business and Finance |
| RCPG | Research Coordination And Planning Group | - | Business and Finance |
| RDA | Radar Data Acquisition | - | Business and Finance |
| RDA | Remote Database Access | - | Business and Finance |
| RDAM | Radar Data Access And Management Format | - | Business and Finance |
| RDAS | Reflectivity Data Acquisition System | - | Business and Finance |
| RDC | Regional Data Center | - | Business and Finance |
| RDCC | Real-time Display And Coordination Center | - | Business and Finance |
| RDF | Real-data Forecast | - | Business and Finance |
| RDF | Radio Direction Finding | - | Business and Finance |
| RDP | Research Data Program | - | Business and Finance |
| RDR | Radar | - | Business and Finance |
| RDSG | Research Data Support Group | - | Business and Finance |
| RDSS | Research Data Support System | - | Business and Finance |
| RDT&E | Research, Development, Test And Evaluation | - | Business and Finance |
| RECOURSE | Revision Control Unifying Related Environments | - | Business and Finance |
| REGCM | Regional Climate Model | - | Business and Finance |
| REGCM2 | Regional Climate Model | - | Business and Finance |
| REREX | Remote Read-out Experiment | - | Business and Finance |
| REU | Research Experiences For Undergraduates | - | Business and Finance |
| RF | Radio Frequency | - | Business and Finance |
| RFC | River Forecast Center | - | Business and Finance |
| RFC | Request For Comment | - | Business and Finance |
| RFF | Research Flight Facility | - | Business and Finance |
| RFF | Resources For The Future | - | Business and Finance |
| RFI | Radio Frequency Interference | - | Business and Finance |
| RFP | Request For Proposal | - | Business and Finance |
| RFQ | Request For Quote | - | Business and Finance |
| RFT | Reverse-flow Thermometer | - | Business and Finance |
| RGB | Red | - | Business and Finance |
| RGP | Reactive Gases And Particles Project | - | Business and Finance |
| RGSP | Review Of Geophysics And Space Physics | - | Business and Finance |
| RH | Relative Humidity | - | Business and Finance |
| RHI | Range-height-indicator | - | Business and Finance |
| RHS | Right-hand Side | - | Business and Finance |
| RI | Research Institute | - | Business and Finance |
| RI# | Richardson Number | - | Business and Finance |
| RIB | Research Internet Backbone | - | Business and Finance |
| RIDDS | Radar Interface And Data Distribution System | - | Business and Finance |
| RIDGE | Ridge Interdisciplinary Global Experiment | - | Business and Finance |
| RINEX | Receiver Independent Exchange Format | - | Business and Finance |
| RISC | Reduced Instruction Set Computer | - | Business and Finance |
| RISE | Radiative Inputs From Sun To Earth | - | Business and Finance |
| RITS | Radiatively Important Trace Substances | - | Business and Finance |
| RJE | Remote Job Entry | - | Business and Finance |
| RMC | RAF Management Council | - | Business and Finance |
| RMC | Regional Meteorological Center | - | Business and Finance |
| RMS | Root-mean-square | - | Business and Finance |
| RNG | Renormalization Group | - | Business and Finance |
